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Photos of hind limb rudiments on modern day whales (and creationist "answers")

Photos (with discussion) of hind limb rudiments found on modern day whales


Photo of hind limb bud on whale embryo


Photo of hind limb bud on dolphin embryo (dolphins are another member of the Cetacean family, along with whales)




CRITICISMS OF THE ABOVE PHOTOS AND EVIDENCE FROM CREATIONISTS ALONG WITH MY REPLIES:


DAVID TYLER writes:


Hi Ed,
Thanks for visiting the BCS web site and for your note. As it happens, the latest issue of "Origins", our journal, has an essay by Paul Garner on "The Whale that Wasn't". I'll forward your post to Paul.


BTW, we're quite comfortable with cetaceans having hind limb rudiments. They are mammals and they have a mammalian body design.


Best regards,
David J. Tyler, on behalf of BCS




TED HOLDEN'S CRITICISM:


From: "Ted Holden"
Sent: Thursday, July 24, 2003 10:35 PM
Subject: Evolution of whales - vestigial hind limbs


There are several things which make whale evolution impossible and not just the question of legs to flippers.


The biggest problem as I see it is baleen. How is a normal predator which kills large animals with its teeth and eats them supposed to start straining plankton through its teeth and somehow or other hold on and survive until his teeth turn into whalebone, 10,000 generations later.


You've got to be seriously stupid to believe anything like that. In fact, the guy who believes that will make Mortimer Snerd look like Albert Einstein by way of contrast.


Ted Holden


Splifford the bat says: Always remember
A mind is a terrible thing to waste; especially on an evolutionist. Just say no to narcotic drugs, alcohol abuse, and corrupt ideological doctrines.


ED's REPLY TO TED HOLDEN:


It's always something with creationists like Ted. If evidence of land-based creatures moving to the sea isn't enough, now they want to know how teeth evolved into baleen. And they add, "baleen disproves evolution could have occured!" So they just keep drawing that line backwards. Now the line is drawn as "Baleen!" Heck, think about the line back when Duane T. Gish of ICR was pumelling even the possibility of whale evolution with his "Cow to Whale" slide.
Evolution's come a long way baby, and it keeps on a-commin.




ANOTHER CREATIONIST:


Since whales are based on the "mammalian body plan" we would expect them to sometimes sprout rudimentary hind limbs on occaision when the plan sometimes gets messed up or mutated.


ED's REPLY:


It would appear that the creationist above has not read the entire article nor taken the time to examine the photos. I wonder of course how the above young-earth creationist might feel about this evidence if he could first be convinced that the world is indeed very old, and that fossil succesion has occured, and see for himself what comparative anatomical changes throughout time, imply.


He probably believes that all the whale fossils were of creatures that lived simultaneously with each other and with dinosaurs and trilobites and marine reptiles, etc. Though I would like him to explain why whales are found in the correct relative geological layers for their comparative anatomy to even suggest evolution from previously living land mammals with peculiar ear bones. Or why modern day whale fossils are not found in layers beneath their obvious precursors but only afterwards. Or why other large denizens of the deep that were reptiles from the age of reptiles are never found buried with the earliest whales nor above them but always beneath them? Those large marine reptiles certainly would have swam in the same environments as the cetaceans (whales and porpoises) if they all lived together. Indeed, with a Flood of the magnitude of the Bible there should be out-of-place-fossils galore, out of place fossil fragments too. Only long eons of time could have separated the fossils as they are separated so completely, right down to bone fragments and micro-fossils (single celled fossilized organisms).


Apparently even Duane T. Gish knows this, as he refuses to debate the age of the earth and has even admitted (much to his fellow creationists' chagrin) that the evidence for fossil succession is a challenge that his fellow young-earthers at ICR have not adequately met:


"When I visited the Institute for Creation Research towards the end of 1978... The associate director is Duane T. Gish, who has a PhD in biochemistry from Berkeley. ... Considering that I believe living things have a common origin and have evolved over a long period of time, and Duane Gish doesn't, there turned out to be a surprising amount of shared ground between us. ... Duane Gish and others of his standing are well aware of this problem [for their young-earth views, i.e., the problem of the age of the earth], but in the end they let their faith over-ride it. When I asked him what were the biggest difficulties for creationist science the points in a debate which he felt least comfortable in answering - he answered after a moment's thought that it was the apparently great age of Earth as shown by the fairly recent advances in radiometric dating; and that the the fossil record could be interpreted as showing ecologically complete ages - the age of invertebrates, the age of fishes, the age of reptiles, and so on up to the present. " [from Hitching F., The Neck of the Giraffe: Or Where Darwin Went Wrong, Pan: London, 1982, pp.115-121]


Of course, to creationist critics it's all merely "part of God's plan" to them, including "body plans" that go awry every now and then and sprout rudimentary hind limbs. And it proves nothing to them that land-based ancestors with special "water-hearing" ear bones preceded species that were more adapted for the water. Proves nothing to them that the earliest whales were so different from later more highly specialized and robust species. Proves nothing to them that the record shows it wasn't "Design," but work done in stages, tinkering with some land mammals over tens of millions of years, during which time most of those ancient species became extinct, rubbish heap designs.


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British Creation Society vs. Whale Evolution

"DAVID TYLER" writes:


Hi Ed,


Thanks for visiting the BCS web site and for your note. As it happens, the latest issue of "Origins", our journal, has an essay by Paul Garner on "The Whale that Wasn't". I'll forward your post to Paul.


BTW, we're quite comfortable with cetaceans having hind limb rudiments. They are mammals and they have a mammalian body design.


Best regards,
David J. Tyler, on behalf of BCS.




Hi David,


Thanks for your quick reply.


I do intend to read Garner's article that you mentioned if it goes online or if you could email it to me.


When I was a young-earth creationist (YEC) I read Doughas Dewar's book THE TRANSFORMIST ILLUSION along with a huge packetful of tracts from the Biblical Creation Society, or was it called the British Creation Movement back then?


Later, I read a book by another Brit, Alan Hayward, titled, CREATION AND EVOLUTION. I wrote Hayward and he sent me his opening statement at a debate he had with a BCS person on the age of the earth. (Hayward is an OEC), and he said that the vote afterwards was in his favor. Hayward's arguments for an old-earth in his book influenced me to move completely away from YEC, even to oppose it as he did. In fact I cited some of Hayward's arguments in a little paper I wrote:


Creationist "Flood Geology" Versus Common Sense -Or- Reasons why "Flood Geology" was abandoned in the mid-1800s by Christian men of science


You wrote that you were "quite comfortable with cetaceans having hind limb rudiments. They are mammals and they have a mammalian body design."


I wonder of course how you (a YEC) might feel about this evidence if you could first be convinced that the world is indeed very old, and that fossil succesion has occured, and see for yourself what comparative anatomical changes throughout time imply.


You currently believe that all the whale fossils were of creatures that lived simultaneously with each other and with dinosaurs and marine reptiles, etc. Though I would like him to explain why whales are found in the correct relative geological layers for their comparative anatomy to even suggest evolution from previously living land mammals with peculiar ear bones. Or why modern day whale fossils are not found in layers beneath their obvious precursors but only afterwards. Or why other large denizens of the deep that were reptiles from the age of reptiles, are never found buried with the earliest whales nor above them but always beneath them?*


*Please don't bring up the alleged "Pleisiosaur carcass," that even Answers in Genesis warns its members against citing: "The Japanese trawler Zuiyo Maru caught a dead plesiosaur near New Zealand'. This carcass was almost certainly a rotting basking shark, since their gills and jaws rot rapidly and fall off, leaving the typical small `neck' with the head. This has been shown by similar specimens washed up on beaches. Also, detailed anatomical and biochemical studies of the Zuiyo-maru carcass show that it could not have been a plesiosaur.


Source: Arguments we think creationists should NOT use


Those large marine reptiles certainly would have swam in the same environments as the cetaceans (whales and porpoises) if they all lived together. Indeed, with a Flood of the magnitude of the Bible there should be out-of-place-fossils galore, out of place fossil fragments too. Only long eons of time could have separated the fossils as they are separated so completely, right down to bone fragments and micro-fossils (single celled fossilized organisms) -- For more on that please see Creationist "Flood Geology" Versus Common Sense -Or- Reasons why "Flood Geology" was abandoned in the mid-1800s by Christian men of science


Even the YEC creation-evangelist Duane T. Gish refuses to debate the age of the earth and has even admitted (much to his fellow creationists' chagrin) that the evidence for fossil succession is a challenge that his fellow young-earthers at ICR have not adequately met:


"When I visited the Institute for Creation Research towards the end of 1978... The associate director is Duane T. Gish, who has a PhD in biochemistry from Berkeley. ... Considering that I believe living things have a common origin and have evolved over a long period of time, and Duane Gish doesn't, there turned out to be a surprising amount of shared ground between us. ... Duane Gish and others of his standing are well aware of this problem [for their young-earth views, i.e., the problem of the age of the earth], but in the end they let their faith over-ride it. When I asked him what were the biggest difficulties for creationist science the points in a debate which he felt least comfortable in answering - he answered after a moment's thought that it was the apparently great age of Earth as shown by the fairly recent advances in radiometric dating; and that the the fossil record could be interpreted as showing ecologically complete ages - the age of invertebrates, the age of fishes, the age of reptiles, and so on up to the present. " [from Hitching F., The Neck of the Giraffe: Or Where Darwin Went Wrong, Pan: London, 1982, pp.115-121]


Of course you are "quite comfortable" as Gish is, being a YEC, because then you can just call everything "part of God's plan," including "body plans" that go awry every now and then and sprout rudimentary hind limbs. And you can be "quite comfortable" with land-based relatives of whales that had special "water-hearing" ear bones and which preceded species that were even more fully adapted for the water. And "quite comfortable" with the earliest whales being so different from later more highly specialized and robust modern species. And finally, "quite comfortable" that the record of fossil succesion shows it wasn't "Design," but a work done in stages, at best, tinkering with some land mammals over tens of millions of years, during which time most of those ancient species became extinct, rubbish heap designs.


I was never quite comfortable myself, even as a creationist, especially once my faith in "Flood geology" explanations ran out.


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Sirenian Evolution: Elephant to Sea Cow (Manatees)

Astonishing photographic evidence of similarities between modern sea cows and elephants. Including photographs with celebrity LeVar Burton from Reading Rainbow.

  • Origin of Sirenians
    Earliest Sirenians, Prorastomus and Protosiren. Timeline of Sirenian Evolution and Extinctions. Images of the four extant manatee and dugong, and the extinct Steller's Seacow.
  • Sirenian Evolution: Elephant to Sea Cow
    Astonishing photographic evidence of similarities between modern sea cows and elephants. Including photographs with celebrity LeVar Burton from Reading Rainbow.
  • Sea Cows, Manatee and Sirenia Evolution
    Up close and personal with LeVar Burton and Manatees video. Photographs of Toenails on Manatee, and discussing diet, eating habits and lifestyle of Sea Cows.
  • Images of Sirenians
    All images illustrated by Sharon Mooney, available for download and public distribution for educational purposes.

    A PARAGRAPH ON SEA COW EVOLUTION BY CHARLES DARWIN FOLLOWED BY A RECENT DISCOVERY OF AN ANCIENT SEA COW FOSSIL WITH HIND LIMBS
    "The Sirenia [which includes the sea cow / manatee - E.T.B.] form a very distinct group of mammals, and one of the most remarkable peculiarities in the existing dugong and lamentin is the entire absence of hind limbs without even a rudiment being left; but the extinct Halitherium had, according to Professor Flower, an ossified thighbone "articulated to a well-defined acetabulum in the pelvis..."
    -- Charles Darwin, The Origin of Species, chapter XI "On the Geological Succession of Organic Beings," "On the Affinities of Extinct Species to each other, and to Living Forms"


    Legged Sea Cow Fossil Found in Jamaica
    By Hillary Mayell
    for National Geographic News
    October 10, 2001


    The nearly complete skeleton of an ancient aquatic mammal with legs has been unearthed in Jamaica. The 50-million-year old skeleton is one of the best examples so far of the evolution from a land animal to an aquatic animal, said Daryl Domning, a paleontologist at Howard University in Washington, D.C., who reported the discovery.


    The skeleton found in Seven Rivers, Jamaica, is a new genus and species of the order Sirenia, which encompasses the ancestors of modern-day manatees and dugongs. Commonly known as sea cows, sirenians are plant-eating mammals that spend their entire lives in water. They started out as land animals, however. This new find fills a significant gap in the fossil record, helping scientists complete the picture of how land animals evolved to sea creatures. "This is the most primitive fossil found so far," said Domning. "We've found others with legs that couldn't support the animal's body weight. But this is the first whole skeleton with legs that could support the animal's body weight out of water, yet has clear adaptations for aquatic life. "We essentially have every stage now," he added, "from a terrestrial animal to one that is fully aquatic."


    Domning's study, for which the National Geographic Society funded the field work, appears in the October 11 issue of Nature.


    Read the entire article.




    EMAIL EXCHANGE WITH PROFESSOR DARYL P. DOMNING, AUTHOR OF SIRENIAN EVOLUTION IN THE NORTH PACIFIC OCEAN


    Dear Professor Domning,


    I am currently seeking to collect pictures portraying the known species of Sirenians and their evolution. You mentioned in your National Geo. article that there are extinct species of Sirenians with rear legs that were too small to support them. Where might I find such pictures on the web or in the literature?


    I have already collected pictures of atavistic hind legs on modern day whales, and pictures of hind leg buds on cetacea fetuses. I am planning to collect photos of Sirenia as well, for the purpose of sharing them with creationists.


    Sincerely, Edward T. Babinski


    PROFESSOR DOMNING'S REPLY


    Dear Mr. Babinski,


    Unfortunately, no one has put much effort into drawing accurate pictures of most of the extinct sirenians, mainly because all the ones from about the end of the Eocene onward looked outwardly not much different from the modern ones, especially as regards hind limbs. Protosiren (Middle Eocene) still had substantial though weak hindlimbs; ones like Eosiren (Late Eocene) probably had vestigial external hindlimbs; but after that there was probably nothing else visible on the outside -- only bony vestiges inside the body outline.


    What you can find are illustrations of the fossil bones themselves; key references are given in my article in Reports of the NCSE, vol. 21, no. 5-6, 2002. I hope this helps -- good luck with the creationists. What have they been saying about sirenians?


    Sincerely,
    Daryl Domning.




    LIFE CHANGING TELEVISION
    by Sharon Mooney
    In the early part of 2000, I developed a strong interest in the Evolution-Creation debate. The evidence had always been available, for instance in the National Geographic magazine which my parents had subscribed to all their life, and on educational television stations like PBS, Discovery and The Learning Channel, but making the error that most young people do, I never paid a lot of attention to the information that was available to me.


    I began paying closer attention to the documentaries on the evolution-creation debate not so long ago, and was amazed by what I soon learned. The information is not new, but my attention span was. PBS broadcasted "Evolution, The Triumph of an Idea" in 2001, and upon seeing their presentation of land mammal to sea mammal, and all the causes scientists have for establishing a relationship between the two, amazed me. In November 2001, National Geographic magazine released "The Evolution of Whales", co-written by Professor Hans Thewissen (a world renown Paleontologist), a real life, modern day "Alan Grant" (Jurassic Park), as I tell people. The article contained images which appeared to indicate remains of hind limbs still exist in some whales.


    Manatee Toe Nails
    "Today's sperm whale has vestigial hind limbs."


    Based on an image found on Page 71, National Geographic MagazineNovember 2001, "The Evolution of Whales"

    I took this information at face value, and simply accepted it as fact, without ever double checking if they had concrete empirical evidence such as photographs. This lead to later conflicts with Fundamentalist Creationists, who claimed there are no photographs. I faithfully believed that this Professor "Hans Thewissen" who co-wrote the article, would not lie. I believed National Geographic must be telling the truth. I had developed a fond trust of National Geographic magazine, since childhood. My parents were Creationists, but they had always subscribed to National Geographic, and encouraged my siblings and myself to read the magazines and books. We had a healthy respect for the National Geographic Society. I still appreciate the assistance they gave our family in matters of science. For instance, when we noticed a strange and beautiful woodpecker that showed up in our backyard. My mother wrote National Geographic, questioning which species of Woodpecker it is, explaining to them the location we lived at, and the general environment. A researcher from National Geographic replied, defining the exact species of woodpecker, explaining it's rarity -- we were lucky to have had one turn up in our backyard, it's diet, it's preferred habitat, and mating rituals. Later, as I was picking butterbeans (we lived on a farm) I noticed an odd species of lady-bug. This unusual insect was at times a peculiar dull shade of off colored orange-brown -- it was chameleonic, and would change colors -- including turning into sparkling gold, just like a drop of gold reflecting the sunlight -- too beautiful to believe it was real! I dubbed it the "Gold bug". I kept seeing this particular type of ladybug in our garden. I had to know more about this fascinating insect. I wrote National Geographic and they replied with the exact species and all pertinent information. I never had cause to question their authority on matters of animal biology.


    After reading numerous claims that no photographs or evidence exists for hind limbs on whales, I began a search for those photographs. I believed photos *must* exist if scientists like this famous Professor Hans Thewissen would say "Vestigial hind limbs exist". The day I went searching, I did not find any photographs, but I did find an article written by a man, by the name of Edward T. Babinski (holding a Bachelor of Science in Biology) posted on EvC Forum."Does evidence of transitional forms exist ? (Hominid and other)" and I contacted him, inquiring on photographs.


    "Ed" Babinski (as I've come to know him in the past couple years) went about the task of tracking down the actual photographs, and combining them with known research on hind limbs on modern whales.


    Creationists denied the existence of hind limbs on whales, and Ed located the photographs which confirm the existence of limbs on whales. [I thank him for that.]


    It is quite easy for Creationists to deny vestigial hind limbs on whales, due to the fact that cetacea (whales and dolphins) are so far along in the evolutionary process, that today little or no evidence remains in their anatomy to demonstrate thier evolutionary history. That is, to say for the common person with no background on biology or paleontology. For scientists, the evidence is abundant and overwhelming. But for the common person, such as myself, modern whales offer only limited evidence of their land-dwelling, quadruped ancestors. For me, that vestigial organs would slowly disappear on whales, is only a matter of common sense -- that is, if Darwinian natural selection is true, and I believe it must be. Aside of the rare fossil finds Paleontologists recover from obscure desert regions where oceans once existed, whales simply do not offer the kind of empirical evidence Creationists demand to see. To elaborate on this point, myself and Ed Babinski had the opportunity to correspond with Professor Hans Thewissen in 2003 on photographs contributed by the Milwaukee Public Museum of their Humpback and Pilot Whale Display, both of which contain vestigial Pelvis bones. Professor Thewissen explained, the mount in the museum does not contain the femur, because it is made of cartilage. That portion of the hind limb on the whale is missing, but yes, the whale has one.


    However, this lack of visual evidence is not the case with Sirenians (Sea Cows, Dugongs, Manatee).

    A note of interest for Sirenian lovers: Hans Thewissen has moved his site, and has added a page on Sirenian fossils!

    Sirenian Populations Around World


    Approximate Sirenian populations/locations.Image Source: Home ArchiveBased on information in National Geographic

    I had a life-changing experience a couple years ago viewing PBS Reading Rainbow episode "Sam the Sea Cow" where LeVar Burton visits various manatee / marine mammal preserves, including Sea World. I stood in awe [along with the information I'd picked up from the PBS "Evolution" series, and National Geographic's "Evolution of Whales"] as I saw LeVar Burton holding a manatee flipper in his hand, seeing it with my own eyes, these "elephant toenails" on a sea mammal! Including numerous other similarities with elephants that Dr. Lowe explained to LeVar Burton and the camera crew. I had trouble digesting that amazing video which you can see by visiting Sam the Sea Cow in Real Media Format. [Click on the "Preview this Video" link]. These are not "hypothesized" vestigial toenails. These toenails exist in our own time, that we can see with our own eyes, in this day and age! There is no denial of toe nails on manatees. The manatee perhaps, will lose their toenails in another twenty thousand years -- perhaps another fifty thousand years. Perhaps another million. Perhaps twenty million years from now. And, when nature has ran its course, and toenails have disappeared from sirenians (if they're not driven to extinction before that time), a Creationist, somewhere, will deny fossilized toenails on sea cows, as they have adamantly denied hind limbs on whales. We are living in a time, where the evolutionary process has not yet finished running its course with Sirenians. We are blessed to see the phenomena of evolution in progress! With Sirenians, unlike the majority of Cetaceans, it's getting there -- but it's not complete. The traces of toe nails (and other traits) remain on the Sea Cow. We're not so fortunate in the case of whales. We would have seen and taken for granted hind limbs on whales, had we lived thirty five million or more, years ago.


    I am very pleased to have been granted permission by the Producers of Reading Rainbow to share this segment of "Sam the Sea Cow" which reveals the toenails and other traits in common with elephants. Along with the photographs (below), please do visit the PBS site and see the video segment for yourself here. [Click on the "Preview this Video" link].




    Sam the Sea Cow about an injured Sea Cow rescued by marine biologists.
    Celebrity host, LeVar Burton examines a Sea Cow close up revealing it's traits in common with elephants.
    Sam The Sea Cow, WMV / Flash Format / Duration - 3:06
    © 1992, Reading Rainbow
    RR is a production and registered trademark of GPN/Nebraska Educational Telecommunications and WNED-TV, Buffalo NY




    FROM ELEPHANT TO SEA COW

    Source of Photographs: PBS Reading Rainbow episode Sam the Sea Cow about an injured Sea Cow rescued by marine biologists. Celebrity host, LeVar Burton examines a Sea Cow close up, revealing it's traits in common with elephants.

    To view this segment of the episode in Real Media video format go to "Preview This Video" link here.

    Reading Rainbow Sam The Sea Cow, WMV / Flash Format / Duration - 3:06


    Original episode available for purchase in DVD or VHS format by visiting
    http://gpn.unl.edu/rainbow/.


    RR is a production and registered trademark of GPN/Nebraska Educational Telecommunications and WNED-TV, Buffalo NY

    Manatee Toe NailsManatee Toe Nails
    Manatee Toe NailsManatee Toe Nails

    LeVar: This is remarkable. I've never been around this many huge animals in the water before. How big are some of the manatees here?


    Mark: The male manatees, when they're adults, run about a thousand to twelve hundred pounds. The females run in the neighborhood of about two thousand pounds.


    LeVar: That's a lot of weight. These animals are really, really large. You know Doctor, a lot of people don't think that manatees are very attractive looking, but I find them really beautiful.


    Mark: Right. Well I think, the thing about manatees is that they're so ugly, they're cute.


    LeVar: Now Becky, what's on the menu today? What are you feeding these manatees?


    Becky: These are vitamin-mineral biscuits. We give them lettuce, cabbage and carrots.


    LeVar: They're vegetarians.

    Manatee Toe NailsManatee Toe Nails
    Manatee Toe NailsManatee Toe Nails

    LeVar: So let's talk about where the manatee comes from Dr. Mark. They're descended from which animal do we think?


    Mark: We think they're descended from the elephant. It's their closest relative on land. And they have a upper lip very similar to an elephant's trunk. Here we go with one reaching and grabbing. ... sort of like an elephant would reach and grab something...


    LeVar: With the end of his trunk? They're sort of like fingers. Then of course the flippers and the nails on the flippers. They look like elephants' toes.


    Mark: Very small nails. Very similar to the elephant.


    LeVar: I love the way their skin feels.


    Mark: And they do have sparse body hairs, very difficult to see, along their back you'll see some very fine hairs.


    LeVar: Oh yeah!


    Becky: Well, I think that makes them a mammal.


    LeVar: Now, Manatees hold their breath like we do. Don't they?


    Mark: Right. Just as they go under water, you'll notice there's a little valve on the nostril that closes and this keeps the water out of their nose. They breathe every three to five minutes on the average.


    Manatee Toe NailsManatee Toe Nails
    Manatee Toe NailsManatee Toe Nails



    SIRENIANS EVOLVED SEPARATELY FROM CETACEANS: MANATEES RELATED TO ELEPHANTS


    Manatees have tough, grayish-brown, wrinkled skin that feels like an elephant's skin. Scientists say that long ago, manatees used to live on the land and eat grass like elephants. Manatees have toenails just like an elephant too. Also, a manatee's big nose is like a short trunk. Manatees use their nose to grab plants and pull them into their mouth -- just like an elephant! Of course, manatees and elephants are very different. Since manatees live in the water today, they don't even have back legs.




    Although scientists often lump sirenians together with the order Cetacea (whales and dolphins) as totally aquatic marine mammals, manatees and the dugong are actually more closely related to elephants, hyraxes, and aardvarks! This group of animals, commonly called sub-ungulates, shares an ancient African ancestor. Which makes manatees and dugongs more closely related to elephants than to dolphins or whales. In fact, scientists often find behavioral, physiological, and genetic similarities between manatees, dugongs and elephants. One major difference between cetaceans and sirenians is their diets. Whales and dolphins eat fish and plankton; some species, like the killer whale, even eat other whales and dolphins. Manatees and dugongs, like elephants, are herbivores. In fact, they are the ONLY marine mammal herbivores alive today! Their diet consists primarily of sea grasses and other aquatic vegetation.





    AQUAGENESIS by Richard Ellis

    AquaGenesis by Richard Ellis available at amazon.com


    Below are some quotes found within the pages of the latter half of AquaGenesis. Richard Ellis has done a thorough job of discussing Sea Mammals and other relevant creatures who shared a land-sea environment in their evolutionary history.


    SOME EXCERPTS FROM AQUAGENESIS
    At many different times in the geological past, terrestrial animals abandoned the ecological accomplishments of their remote ancestors, the air-breathing fishes, to reinvade the sea. Ichthyosaurs, plesiosaurs, crocodiles, turtles, snakes, penguins, whales, and seals, to cite a few obvious groups, have established themselves very well in marine environments. In doing so, they have mimicked the shapes of fish. However, fish have effectively invaded the land only once, 365 million year ago, and these were the ancestors of succeeding land-dwelling backboned mammals. No fish has since emerged from the water to mimic the shapes of the dominant backboned animals on land. How is it that land-dwelling creatures, though initially adapted imperfectly to living in water, can successfully compete with the marine creatures whose ancestors never left the sea, but the reverse never occurs?
    --Dale Russell, 1989


    "Because it spends most of its time on land or ice, and enters the water only occasionally, the polar bear is not usually considered a marine mammal. Ursus maritimus swims well, but only to get from place to place. During the past 25,000 years, it has evolved from a brown, temperate-zone, land-based bear into a white, semiaquatic, cold-weather bear, and is probably a marine mammal in the making.Richard Ellis (footnote), page 175, "AquaGenesis"


    If you have collected fossils to any great extent in marine Tertiary deposits of tropical or once-tropical latitudes, you have probably come across cylindrical pieces of thick, dense, vertebrae bone several centimeters in diameter that someone told you were the ribs of sirenians, or seacows. You may even have learned to apply the term "pachyostotic" to such bones. Inquiring further, you probably learned that seacows (manatees and dugongs) are the legendary mermaids, that they are the nearest living relatives of elephants, and that they all replace their teeth horizontally, back to front, just like elephants do. Such is education: a random mixture of truth and error, hopefully favoring the former.
    --Daryl Domning, 1999


    Mimicry is a difficult concept to justify in terms of natural selection. How is it possible for totally different animals to have achieved the same shape, coloration, and size? Or for a creature to develop an imexplicable resemblance to a unrelated species, as with the dwarf sperm whales' "gills"? The leafy sea dragon, a sea horse, has evolved a costume of frilly protuberances that make it disappear in the weeds and coral near which it lives. The same is true of the sargassum fish, which looks almost exactly like the sargassum weed in which it lives. Occassionally we read that these creatures grew to look like leaves or plants so that they could fool predators, but this suggests a determinism that Darwinists say is completely lacking in the evolutionary process. Richard Dawkins (1996) sees no problem at all with 'mimicry', writing that "it is enough to say that we are sure this resemblance, and other examples of 'mimicry', are not accidental. They are either designed or they are due to some process that produces results just as impressive as design." His final answer? "That magnificently non-random process which creates an almost perfect illusion of design . . . .Darwinian natural selection."
    --Richard Ellis, (footnote), page 235, AquaGenesis


    Some groups of mammals became completely aquatic like the whales and the Sirenia (dugongs and manatees), others like seals almost so, and many others, such as Polar bears, otters, beavers, water voles, etc., became partially aquatic. I then put forward the thesis that perhaps man himself had such a phase of semiaquatic life.
    --Sir Alister Hardy, 1960 quoted by Richard Ellis, page 243


    The news about the aquatic descent of elephants was startling enough to make many newspapers and television news programs when the paper was published in May 1999, but Elaine Morgan was way ahead of Gaeth, et al. In her 1985 revision of 'The Descent of Woman', she wrote:

    "We know that one of the elephant's nearest kin went into the sea and stayed there permanently, for the elephant's closest cousin is the sea cow. We know that early species of elephant developed weird and pointless-looking dental arrangements quite useless to land dwellers. There were, for instance, the shovel-tuskers, Ambledone and Platybelodon grangeri. Now shovels and spoons as a natural endowment are invaluable to water-feeders, like ducks and spoonbills and platypuses, but why on Earth would a land-dwelling animal want to scoop up a shovelful of Earth? Another primitive elephant had tusks that pointed down, like a walrus's."

    Elephants are good swimmers now, so there is every reason to assume that they were good swimmers in the past, and for swimmers, she wrote "a snorkel makes sense."
    --Richard Ellis, page 250-251, AquaGenesis


    The earliest fossils were found in Hungary, but they are fragmentary and give little idea of what the animal actually looked like, or even whether it was aquatic. The Middle eocene sea cow, Prorastomus sirenoides, was found in Jamaica in 1855, but again not enough material was available to reconstruct that animal. Additional fossil material has been found in Jamaica, but, wrote Savage, Domning, and Thewissen (1994), "This odd little sea cow has been a difficult morsel for science to digest." Nevertheless, Prorastomus sirenoides "is the best available approximation to a structural ancestor of the Sirenia," and was "probably an amphibious but mainly aquatic quadruped that inhabited coastal rivers and embayments. It was probably a selective browser on floating and emergent aquatic plants and, to a minor degree, on sea grasses."
    --Richard Ellis, Marine Mammals - "The Sea Cows", AquaGenesis, Page 177


    Whatever other appellations might be applied to these animals, "beautiful" is not the first one that springs to mind. Although they bear a superficial resemblance to some of the other marine mammals such as pinnipeds and cetaceans, sirenians have no evolutionary relationships with them. In fact, paleontologists have classified them as subungulates and lumped them together with such varied company as elephants, hyraxes, and aardvarks. Like the sirenians, all these animals lack a clavicle (collar bone) and have nails or hooves instead of claws.
    --Richard Ellis (footnote, page177)


    The first manateelike animla, dating from about 15 million years ago, was Protosiren, yet it lacked the replacement teeth that enable modern manatees to eat abrasive plant material. Recently, Domning and Gingerich (1994) suggested that Protorastamus and Protosiren were quadrupedal amphibious creatures that lived along the seashores. What did they look like? Domning (1991) wrote, "The Seven Rivers [Jamaica] prorastomids, which are slightly more derived than Prorasatomus itself, were pig-sized quadrupeds with long trunks, and a substantial though not powerfully-muscled tail." Certain anatomical characteristics "indicate that they were more aquatic than modern hippopotami; they probably fed as well as rested in the water, but at least the earlier of them could probably support their weight onland. In a 1916 paper, "Sea Cows, Past and Present," Frederic Lucas wrote: "It would of course be one link in the chain, one step towards a four-footed animal, if we could find a four-paddled porpoise, but none has yet come to light, and here is where the sea cow comes forward with an important bit of evidence. When paleontologists were hunting in the Fayum, Egypt, for ancestors of existing elephants, they came upon the remains of a manatee, not unlike those of today, save that it possessed four well-developed paddles; and because it was so evidently the predecessor of the modern sea cows, it was named Eosiren," from Eos, the Greek goddess of dawn. In fact, says Domning, "Eosiren libyca (late Eocene) had vestigial hind limb bones, but the hind limbs probably did not show on the outside of the body. In no case have we actually found a complete hind foot for any of these, paddlelike or otherwise. Lucas's statement is a broadly valid inference based on the pelvic bones, which were the only relevant elements available in his time" (personal communication, 2000).


    AQUAGENESIS by Richard Ellis
    AquaGenesis by Richard Ellis available at amazon.com


    The above quotes were excerpts from Richard Ellis' AquaGenesis which I highly recommend to anyone who wishes to find a book covering an indepth history of animal life from their beginnings in the ocean to where they emerged on land, and beyond.


    Make a shorter URL to this article. Highlight link and "Copy To Clipboard"

  • Origin of Sirenians

    Earliest Sirenians, Prorastomus and Protosiren. Timeline of Sirenian Evolution and Extinctions.

    Sirenian Evolution
    by Sharon Mooney, with excerpts and paraphrased from Daryl P. Domning, Howard University, Washington, DC
    Encyclopedia of Marine Mammals
    Academic Press, 20002; Perrin, W├╝rsin and Thewissen


    Sirenia are the order of placental mammals which comprise modern sea cows (manatee and dugongs) and their extinct relatives. They are the only herbivorous marine mammals now in existence and the only group of herbivorous mammals to have became completely aquatic. Sirenians have a 50 million year old fossil record (early Eocene-Recent). They attained modest diversity during the Oligocene and Miocene, but have since declined as a result of climatic cooling, oceanographic changes, and human interference. Two genera and four species are extant: Trichechus which includes three species of Manatee that live along the Atlantic Coasts and in rivers and coastlines of the Americas and Western Africa. Amazonian Manatee live only in fresh water and Dugongs are found in the Indian and Pacific oceans.


    West Indian Manatee

    Family: Trichechidae
    West Indian Manatee
    Trichechus manatus
    Subspecies: Trichechus manatus latirostris (Florida manatee) and Trichechus manatus manatus (Antillean manatee)
    Source: Sirenians of the World
    Public Access Image may be redistributed, on condition all original credits are kept intact.


    Amazonian Manatee

    Family: Trichechidae
    Amazonian Manatee
    Trichechus inunguis
    Source: Sirenians of the World
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    West African Manatee

    Family: Trichechidae
    West African Manatee
    Trichechus senegalensis
    Source: Sirenians of the World
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    Dugong

    Family: Dugongidae
    Dugong
    Dugong dugon
    Source: Sirenians of the World
    Public Access Image may be redistributed, on condition all original credits are kept intact.


    Steller's Sea Cow

    Family: Dugongidae
    Steller's Sea Cow
    Hydrodamalis gigas

    At one time, the Steller's sea cow was found in the cold waters of the Bering Sea, but it was hunted to extinction within 27 years of its discovery in 1741. The largest sirenian on record, the Steller's sea cow grew up to nine meters (30 feet) in length and weighed around four metric tons (approximately 4.4 tons).

    Source: Sirenians of the World
    Public Access Image may be redistributed, on condition all original credits are kept intact.


    Sirenian Origins
    Sirenians' closest living relative are Proboscidea (elephants). Tethytheria, are a larger group comprised of Sirenia, Proboscidea, extinct Demostylia and likely the extinct Embrithopoda. Tethyeria appear to have evolved from primitive hoofed mammals known as condylarths, along the shores of the ancient Tethys sea.
    The tethyeria, combined with Hyracoidea (hyraces) form an inclusive group called Paenungulata. Paenungulata and Tethytheria (especially the latter) are among the least controversial mammalian orders, with strong support from morphological and molecular research. The ancestry of sirenia is remote from cetacea and pinnipeds, though re-evolving an aquatic lifestyle simultaneously.


    Fossil History
    The first appearance of Sirenians in the fossil record was during the early Eocene, and by the late Eocene, sirenians had significantly diversified. Inhabitants of rivers, estuaries, and nearshore marine waters, they were able to spread rapidly. The most primitive sirenian known to date, Prorastomus, was found in Jamaica, not the Old World.


    Prorastomus, Early Sirenian found in Jamaica
    Prorastomus

    Based on Sagascience Evolution and Daryl P. Domning
    Public Access Image may be redistributed, on condition all original credits are kept intact.

    The earliest known sea cows, of the families Prorastomidae and Protosirenidae, are both confined to the Eocene, were about the size of a pig, four legged amphibious creatures. By the time the Eocene drew to a close, came the appearance of the Dugongidae and Sirenians had acquired their familiar fully-aquatic streamliined body with flipper-like front legs with no hind limbs, powerful tail with horizontal caudal fin, with up and down movements which move them through the water, like Cetaceans.


    Protosiren

    Protosiren
    Based on Cranial Morphology of Protosiren fraasi, (Mammalia, Sirenia) from the Middle Eocene of Egypt: A New Study Using Computed Tomography

    Adapted for web by Sharon Mooney (2006)
    New reconstruction of type skull of Protosirenfraasi, CGM 10171, with additions from SMNS 10576. Dentary is shown in outline, based on CGM 42297, which may be part of type specimen (see Andrews, 1906). Reproduced ca. 0.45 x natural size. Abbreviations (after Domning, 1978, with additions): AC, alisphenoid canal; AS, alisphenoid; c', upper canine alveolus; EO, exoccipital; FR, frontal; 1' etc., upper incisor alveoli; J, jugal; MI etc., lower molars; MF, mastoid foramen; MX, maxilla; OC, occipital condyle; P1 etc., upper premolar alveoli; PA, parietal; PM, premaxjlla; SO, supraoccipital; SQ, squamosal; SR, sigmoid ridge.
    Public Access Image 500 px and Protosiren 750 px may be redistributed, on condition all original credits are kept intact.


    The last of the Sirenian families who made their appearance, Trichechidae, apparently arose from early Dugongids in the late Eocene or early Oligocene. The current fossil record documents all major stages in hindlimb and pelvic reduction from completely terrestrial morphology to the extreme reduction in modern manatee pelvis, providing an example of dramatic evolutionary change among fossil vertebrates.


    Sirenian Locomotion
    Evolution in Sirenian Locomotion

    Based on Marine Mammals: Evolutionary Biology, Annalisa Berta, James L. Sumich
    Public Access Image may be redistributed, on condition all original credits are kept intact.


    Skeleton of Metaxytherium floridanum - Early Sirenian

    Metaxytherium floridanum

    Based on Encyclopedia of Marine Mammals
    Skeleton of Metaxytherium floridanum, a Miocene halitheriine dugongid. Total length about 3.2 meters. After Domning (1988); original image, Journal of Vertebrate Paleontology. Re-illustrated by Sharon Mooney.
    Public Access Image 750 px and Metaxytherium floridanum 500 px may be redistributed, on condition all original credits are kept intact.


    Since sirenians first evolved, they were herbivores, likely depending on seagrasses and aquatic angiosperms (flowering plants) for food. To the present, almost all have remained tropical, marine and consume angiosperms. Sea cows are shallow divers with large lungs, they have heavy skeletons to help them stay submerged. The bones are pachyostotic (swollen) and osteosclerotic (dense), especially the ribs which are often found as fossils.


    Eocene sirenians, like Mesozoic mammals but in contrast to other Cenozoic ones, have five instead of four premolars, giving them a 3.1.5.3 dental formula. Whether this condition is truly a primitive retention in Sirenians is still under debate.


    Although cheek teeth are relied on for identifying species in other mammals, they do not vary to a significant degree among Sirenians in their morphology, but are almost always low-crowned (brachyodont) with two rows of large, rounded cusps (bunobilophodont). The easiest identifiable parts of sirenian skeletons are the skull and mandible, especially the frontal and other skull bones. With the exception for a pair of tusk-like first upper incisors present in most species, front teeth (incisors and canines) are lacking in all, except the earliest sirenians.


    DUGONGIDAE
    Dugongids comprise the majority of specimens that compose the known sirenian fossil record. The basal members of this family are placed in the Eocene-Pliocene, and subfamily Haliteriinae. This group includes the fossil genera Halitherium and Metaxytherium.


    Metaxytherium gave rise in the Miocene to the Hydrodamalinae, an endemic North Pacific lineage that ended with Steller's sea cow (Hydrodamalis) - the largest sirenian that ever emerged, with a length of up to 9 meters or more. This species was also the only one which make a successful adaptation to temperate and cold waters, and diet of marine algae. It was completely toothless and its truncated, claw like flippers which it used for gathering plants and fending off from rocks, lacked the presence of phalanges (finger bones). Humans hunted Steller's Seacow to extinction in the eighteenth century.


    Another offshoot of Halitheriinae, the subfamily Dugonginae, appeared in the Oligocene. Most dugongines appear to have been specialists at digging out and eating tough, buried rhizomes of seagrasses; for this purpose many had large, self-sharpening blade-like tusks (Domning, 2001). Modern Dugong is the only survivor of this group, but it has reduced dentition (cheek teeth having only thin enamel crowns, which quickly wear off and leave simple pegs of dentine. For this reason, the dugong likely shifted toward a more delicate diet, consisting of seagrasses and ceased using its tusks for digging.


    TRICHECHIDAE
    The Trichechidae have by far more a scant fossil record than dugongids. Their definition has been widened to incorporate Miosireninae, a little-known pair of genera that inhabited NW Europe in the late Oligocene and Miocene. Miosirenines had massively reinforced plates and dentitions that may have been used for crushing shellfish. Such diet in sirenians living around the North Sea seems of little surprise considering modern dugongs and manatee near the climatic extremes of their ranges are known to consume invertebrates in addition to plants.


    Manatees are now placed in the subfamily Trichechinae. They first made their appearance in the Miocene, represented by Potamosiren from fresh water deposits in Columbia. Much of trichechine history was likely spent in South America, from where they spread to North America and Africa only in the Pliocene or Pleistocene.


    It was during the late Miocene, manatees living in the Amazon basin apparently adapted to a diet of abrasive freshwater grasses, and this innovation is still used by their modern descendants. Interestingly, they continue to add on extra teeth to the molar series their entire lifetime. As worn teeth fall out at the front, the whole tooth row slowly shifts to the front to make room for new teeth erupting in the rear. This horizontal tooth replacement has often been likened, incorrectly, to that of elephants, but the latter are only limited to three molars. Only one other mammal, an Australian rock wallaby (Peradorcas concinna) has truly evolved the same kind of tooth replacement system, found in manatees.
    Adapted from Sirenian Evolution, Daryl P. Domning, Howard Encyclopedia of Marine Mammals, pp. 1083-1086


    Sirenian Evolution Chart

    Source: Encyclopedia of Marine Mammals


    Set to web by Sharon Mooney, 2006. Image may be re-distributed on condition all original credits are kept intact, for public access image (Sirenian Evolution Chart, white background.)


    Sirenians are relatively large herbivorous mammals that inhabit warm, near-shore, marine waters today. They made their first appearance in the early middle Eocene some 50 million years ago. The oldest sirenians known to date come from the early middle Eocene of Jamaica. These belong to two genera and species: Prorastomus sirenoides (Owen, 1855; Savage et al., 1994) and Pezosiren portelli (Domning, 2001). The fossil record documents a gradual transition from amphibious ancestral forms like these, with well developed hind limbs attached to a multivertebral sacrum (Domning, 2001), to living representatives such as Trichechus manatus and Dugong dugon that are fully aquatic and have hind limbs reduced to internal vestiges. Eocene sirenians have a reasonably well documented evolutionary history, and are known from all continents except Australia and Antarctica. Protosiren, classified in the monotypic family Protosirenidae, represents one of the more widely distributed Eocene genera, ranging across the southern part of the eastern Tethys Sea from North Africa (Egypt) to South Asia (Indo-Pakistan). Protosiren is known from skulls and partial skeletons (Abel, 1907; Domning and Gingerich, 1994; Gingerich et al., 1994, 1995). It is distinctive and easily recognized from postcranial elements because thoracic vertebrae have a large oval to keyhole-shaped neural canal, articular surfaces of rib heads are generally roughened rather than smooth (indicating that they were connected exclusively by ligaments or flexible cartilage rather than synovial joints), and ribs lack pachyostosis.


    Protosiren is represented by three species described previously (see Figure 1 for geographic distribution). The first, Protosiren fraasi, was named by Abel (1907) on the basis of a well preserved skull and some postcranial remains (first described by Andrews, 1906). These came from the Lower Building Stone Member of the Mokattam Limestone of Cairo (Egypt), which is middle Lutetian in age (early middle Eocene, ca. 45-46 Ma; Gingerich, 1992). The second species, P. smithae, was described and named by Domning and Gingerich (1994). This is a larger species, and it is more derived than P. fraasi morphologically in details of the skull. All known specimens of P. smithae were collected from the Gehannam and Birket Qarun formations in Wadi Hitan (Whales Valley or Zeuglodon Valley), located on the western margin of the Fayum Depression in Egypt. P. smithae is latest Bartonian to earliest Priabonian in age (latest middle to earliest late Eocene, ca. 36-37 Ma; Gingerich, 1992). The third species of this genus, P. sattaensis, was described by Gingerich et al. (1995). This is a large species that is slightly more primitive than P. smithae in having a larger obturator foramen and longer femur (Gingerich et al., 1995, 1997).


    Protosiren is distinctive among sirenians in having large keyhole-shaped neural canals perforating thoracic vertebrae, generally having cartilaginous rather than synovial articulations of rib heads, and lacking rib pachyostosis. Protosiren eothene differs from other species of Protosiren in being smaller (anterior thoracic centra are about 10-12% shorter than those of P. fraasi), in having at least partially synovial rib head articulations with vertebrae, and in having well formed but distinctly small rib tubercula relative to the size of the rib heads.
    Thoracic vertebrae T1 and T2 are represented by centra only. These are weathered, but otherwise undeformed. The centrum of T1 is hemicylindrical and more nearly the length of T2 than would be expected by comparison with anterior thoracics in later Protosiren. This may imply that the neck and cervical vertebrae of P. eothene were longer than those of later Protosiren.


    Thoracic vertebrae of Protosiren


    Thoracic vertebrae of Protosiren spp. (Protosirenidae), Eosiren sp. (Dugongidae), and Trichechus manatus (Trichechidae).

  • A-B, T3 and T5 of Protosiren eothene from the early middle Eocene of Pakistan (GSP-UM 3487, holotype).
  • C, T12 of Protosiren sattaensis (GSP-UM 3001) from the late middle Eocene of Pakistan.
  • D, T8 of Protosiren smithae (UM 101224) from the latest middle Eocene of Egypt.
  • E, T5 of Eotheroides sp. (UM uncat.) from the latest middle Eocene of Egypt.
  • F, T3 of Trichechus manatus from the Recent of Florida (UMMZ 106206). Note the large vertebral canal with a keyhole-shaped cross section in Protosiren vertebrae.
    Source: Philip D. Gingrich, New Species of Protosiren (Mammalia, Sirenia) From The Early Middle Eocene of Balochistan (Pakistan)

    Ancestors to Sirenians (dugongs & manatees)
    The ancestors of sirenians are not known. No sirenian-like fossils are known from before the Eocene.


    "Prorastomus is generally intermediate in structure between other tethytheres and later Sirenia, although perhaps it is not directly ancestral to any known later sirenians. Its notable sirenian features include the inflated rostrum, pachyostotic skull, retracted enlarged nares, and five premolars."
    p. 468, Fossil Record, Tethytheres: Sirenians and Desmostylians, R. Ewan Fordyce

    Early Eocene -- fragmentary sirenian fossils known from Hungary.
    Prorastomus (mid-Eocene) -- A very primitive sirenian with an extremely primitive dental formula (including the ancient fifth premolar that nearly all other mammals lost in the Cretaceous).
    Protosiren (late Eocene) -- A sirenian with an essentially modern skeleton, though it still had the very primitive dental formula, possibly split into the two surviving lineages:

  • Dugongs: Eotheroides (late Eocene), with a slightly curved snout and small tusks, still with the primitive dental formula. Perhaps gave rise to Halitherium (Oligocene) a dugong-ish sirenian with a more curved snout and longer tusks, and then to living dugongs, very curved snout & big tusks.
  • Manatees: Sirenotherium (early Miocene); Potamosiren (late Miocene), a manatee-like sirenian with loss of some cheek teeth; then Ribodon (early Pliocene), a manatee with continuous tooth replacement, and then the living manatees.
    Transitional Vertebrate Fossils FAQ



    Images of Sirenians, Sea Cows; Dugong and Manatee


    Sirenia are the order of placental mammals which comprise modern sea cows (manatee and dugongs) and their extinct relatives. They are the only herbivorous marine mammals now in existence and the only group of herbivorous mammals to have became completely aquatic. Sirenians have a 50 thousand year old fossil record (early Eocene-Recent). They attained modest diversity during the Ogliocene and Miocene, but have since declined as a result of climatic cooling, oceanographic changes, and human interference. Two genera and four species are extant: Trichechus which includes three species of Manatee that live along the Atlantic Coasts and in rivers and coastlines of the Americas and Western Africa. Amazonian Manatee live only in fresh water and Dugongs are found in the Indian and Pacific oceans.



    Metaxytherium floridanum
    Metaxytherium Floradanum - Early Sirenian
    metaxytherium_floridanum2.jpg (500x143 - 19 K)
    metaxytherium_floridanum.jpg (750x215 - 40 K)
    Based on Encyclopedia of Marine Mammals

    Skeleton of Metaxytherium floridanum, a Miocene halitheriine dugongid. Total length about 3.2 meters. After Domning (1988); original image, Journal of Vertebrate Paleontology. Re-illustrated by Sharon Mooney, 2006.
    Public Access images may be redistributed, on condition all original credits are kept intact.
    Evolution in Sirenian Locomotion
    Evolution in Sirenian Locomotion
    sirenian_locomotion.gif (500x300 - 16 K)
    Based on Marine Mammals: Evolutionary Biology, Annalisa Berta, James L. Sumich
    Evolution in Sirenian Locomotion. Re-illustrated by Sharon Mooney, 2006
    Public Access images may be redistributed, on condition all original credits are kept intact.
    West Indian Manatee
    West Indian Manatee
    west_indian_manatee.jpg (500x204 - 19 K)
    Based on Sirenians of the World
    Re-illustrated by Sharon Mooney, 2006
    Public Access images may be redistributed, on condition all original credits are kept intact.
    West African Manatee
    West African Manatee
    west_african_manatee.jpg (500x248 - 23 K)
    Based on Sirenians of the World
    Re-illustrated by Sharon Mooney, 2006
    Public Access images may be redistributed, on condition all original credits are kept intact.
    Steller's Sea Cow
    Steller's Sea Cow
    stellers_sea_cow.jpg (500x158 - 16 K)
    Based on Sirenians of the World
    Re-illustrated by Sharon Mooney, 2006
    Public Access images may be redistributed, on condition all original credits are kept intact.
    Dugong
    Dugong
    dugong.jpg (500x191 - 16 K)
    Based on Sirenians of the World
    Re-illustrated by Sharon Mooney, 2006
    Public Access images may be redistributed, on condition all original credits are kept intact.
    Amazonian Manatee
    Amazonian Manatee
    amazonian_manatee.jpg (500x209 - 17 K)
    Based on Sirenians of the World
    Re-illustrated by Sharon Mooney, 2006
    Public Access images may be redistributed, on condition all original credits are kept intact.
    Sirenian Evolution Chart
    Sirenian Evolution Chart
    (Manatee, Dugong, Sea Cows)
    sirenians_evolution_graph.gif
    (500x881 - 46 K)
    Based on Encyclopedia of Marine Mammals
    Re-illustrated by Sharon Mooney, 2006
    Public Access images may be redistributed, on condition all original credits are kept intact.
    Sirenian Evolution Chart
    Protosiren Fraasi, 1906, Andrews
    protosiren_andrews_1906_750.jpg (750x814 - 149 K)
    protosiren_andrews_1906_500.jpg (500x542 - 73 K)
    protosiren_andrews_1906.jpg (860x933 - 201 K)
    Type specimen of Protosiren fraasi Abel as illustrated, 113 natural size, by Andrews (1906) [CGM 101711. Type is a nearly complete cranium shown here in A, ventral view; C, posterior view; and D, dorsal view. B shows worn surface of right I' tusk (crowns of left and right I' tusks are preserved as casts in NHML and UM replicas of the type made at the turn of the century, but they are no longer preserved in the original type). Reconstruction of premaxillary rostrum shown here is too long and straight (plaster reconstruction, now missing in original type, is shown with crosshatching). Andrews (1906) and Abel (1928) interpreted P4 or dp4 as having multiple roots, but Protosiren is now known to have retained both P4 and P' as single-rooted teeth.
    Based on Cranial Morphology of Protosiren fraasi, (Mammalia, Sirenia) from the Middle Eocene of Egypt: A New Study Using Computed Tomography
    Public Access images may be redistributed, on condition all original credits are kept intact.
    Protosiren Fraasi
    Protosiren Fraasi from Egypt
    protosiren_750_nolabels.jpg (750x445 - 52 K)
    protosiren_750_labels.jpg (750x445 - 61 K)
    protosiren_750_5_premolar.jpg (750x445 - 56 K)
    protosiren_500_nolabels.jpg (500x297 - 27 K)
    protosiren_500_labels.jpg (500x297 - 32 K)
    protosiren_500_5_premolar.jpg (500x297 - 29 K)
    New reconstruction of type skull of Protosirenfraasi, CGM 10171, with additions from SMNS 10576. Dentary is shown in outline, based on CGM 42297, which may be part of type specimen (see Andrews, 1906). Reproduced ca. 0.45 x natural size. Abbreviations (after Domning, 1978, with additions): AC, alisphenoid canal; AS, alisphenoid; c', upper canine alveolus; EO, exoccipital; FR, frontal; 1' etc., upper incisor alveoli; J, jugal; MI etc., lower molars; MF, mastoid foramen; MX, maxilla; OC, occipital condyle; P1 etc., upper premolar alveoli; PA, parietal; PM, premaxjlla; SO, supraoccipital; SQ, squamosal; SR, sigmoid ridge.
    Based on Cranial Morphology of Protosiren fraasi, (Mammalia, Sirenia) from the Middle Eocene of Egypt: A New Study Using Computed Tomography
    Re-illustrated by Sharon Mooney, 2006
    Public Access images may be redistributed, on condition all original credits are kept intact.
    Eotheroides aegyptiacum
    Eotheroides aegyptiacum
    eotheroides_aegyptiacum_702
    (702x988 - 132 K)
    eotheroides_aegyptiacum_500
    (500x704 - 72 K)
    Type specimen of Eotheroides aegyptiacum (Owen) as illustrated, natural size, by Owen (1875) [specimen is now catalogued as NHML 467221. Type is a natural stone endocast shown here in A, right lateral view; B, dorsal view; and C, ventral view. Abbreviations are as follows: a, "pons Varolii"; b, anterior myelonal columns; c, limit of posterior myelonal columns;f, falx cerebri; o, optic nerve; r, tramverse ridge separating impressions of basisphenoid and basioccipital; p, pedicle of pituitary body; R, rhinencephalon (olfactory bulb); tr, trigeminal nerves; v, upper vermiform process; x, lateral myelonal columns; 5, prominence anterior to sylvian fissure. Illustration and abbreviations reproduced from Owen (1875).
    Based on Cranial Morphology of Protosiren fraasi, (Mammalia, Sirenia) from the Middle Eocene of Egypt: A New Study Using Computed Tomography
    Public Access images may be redistributed, on condition all original credits are kept intact.
    Cranium of Protosiren fraasi
    Cranium of Protosiren fraasi
    protosiren_cranium_750.jpg (735x1024 - 106 K)
    protosiren_cranium_500.jpg (500x696 - 63 K)
    Cranium of Protosiren fraasi, A Dorsal, B left lateral, C palatal views
    Priem referred his dentary to the same taxon as Andrews' CGM 42297, possibly anticipating that it would look like CGM 42297 when fully adult. Then Priem, citing Abel (1904, 1906), called Andrews' specimen, and hence his own, Protosirenfrmi. Later Sickenberg (1934) considered Priem's dentary "probable" to represent P. fraasi and referred no other dentaries to this species (inexplicably ignoring CGM 42297). Thus small dentaries with very narrow symphyses have come to typify Protosiren (compare Domning et al., 1982, figs. 20, 21, and 34). However, specimens collected in Wadi Hitan (Zeuglodon Valley) in Egypt in recent years show that Protosiren there has a large dentary with large molars, and a wide mandibular rostrum with well-spaced alveoli for all anterior teeth Domning and Gingerich, 1994), while Eotheroides has the smaller dentary with smaller molars and a narrower rostrum (like Priem's dentary). Andrews was correct to place CGM 42297 in the same taxon as CGM 10171, and it might even be part of the type specimen (fide Andrews, 1906, p. 210). Both represent Protosiren fraasi.
    Based on Cranial Morphology of Protosiren fraasi, (Mammalia, Sirenia) from the Middle Eocene of Egypt: A New Study Using Computed Tomography
    Public Access images may be redistributed, on condition all original credits are kept intact.

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  • Sea Cows, Manatee and Sirenia Evolution

    Up close and personal with LeVar Burton and injured Manatees. Photographs of Toenails on Manatee, and film clip discussing eating habits and lifestyle of Sea Cows.
    • Origin of Sirenians
      Earliest Sirenians, Prorastomus and Protosiren. Timeline of Sirenian Evolution and Extinctions. Images of the four extant manatee and dugong, and the extinct Steller's Seacow.
    • Sirenian Evolution: Elephant to Sea Cow
      Astonishing photographic evidence of similarities between modern sea cows and elephants. Including photographs with celebrity LeVar Burton from Reading Rainbow.
    • Sea Cows, Manatee and Sirenia Evolution
      Up close and personal with LeVar Burton and Manatees video. Photographs of Toenails on Manatee, and discussing diet, eating habits and lifestyle of Sea Cows.
    • Images of Sirenians
      Available for download and public distribution for educational purposes.



    Sam the Sea Cow about an injured Sea Cow rescued by marine biologists.
    Celebrity host, LeVar Burton examines a Sea Cow close up revealing it's traits in common with elephants.
    Sam The Sea Cow, WMV / Flash Format / Duration - 3:06
    © 1992, Reading Rainbow
    RR is a production and registered trademark of GPN/Nebraska Educational Telecommunications and WNED-TV, Buffalo NY



    Sirenian Evolution: Elephant to Sea Cow (Manatees)
    Astonishing photographic evidence of similarities between modern sea cows and elephants. Including photographs with celebrity LeVar Burton from Reading Rainbow.


    manatee
    Manatee have a large beaver-like tail used to propel their 1000-2000 lb bodies.
    manatee
    Manatee are "gentle giants", whose greatest natural enemy, is man. Curious manatee are often injured by boat propellers. LeVar Burton speaks with the professionals who work with injured sea cows, and gets up-close with the manatee. Like all other mammals, the sea cow has hair covering its body.
    manatee
    Manatee have finger-like appendages that "grab food", similar to how the elephant uses its trunk.
    manatee
    manatee
    manatee
    Manatee have tiny valves protecting their nostrils, as they graze on vegetation under water. Sea Cows return to the surface every 3 to 5 minutes to breathe.

    And.. like elephants, Manatee have toe nails on their flippers.


    Some of them have even lost their toe nails, and developed smooth paddles like Cetaceans.

    "The smallest member of the family Trichechidae, the Amazonian manatee has smooth skin and no nails on its flippers and feeds on freshwater vegetation."

    Manatee Toe Nails


    Manatee Toe Nails


    Manatee Toe Nails


    Manatee Toe Nails


    Manatee Toe Nails


    Manatee Toe Nails


    Manatee Toe Nails



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