mesonychids limbs and tail

The similarity in dentition and skull may be the result of primitive ungulate structures in related groups independently evolving to meet similar needs as predators; some researchers have suggested that the absence of a first toe and a reduced metatarsal are basal features (synapomorphies) indicating that mesonychids, perissodactyls, and artiodactyls are sister groups. Whales originated from aquatic artiodactyls in the Eocene epoch of India. These earliest cetaceans were not like the whales we know today, and only recently have paleontologists been able to recognize them. Which embryo is human? They may not have included hypercarnivores (comparable to felids); their teeth were not as effective at cutting meat as later groups of large mammalian predators. If mathematical, chemical, physical and other formulas are not displayed correctly on this page, please useFirefox or Safari, This article is about the prehistoric ungulate. The molars were laterally compressed and often blunt, and were probably used for shearing meat or crushing bones. As you well know, normal matter here on Earth is, Mesonyx and the other mesonychid mesonychians (mesonychians part IV), Because we all love Paleogene 'ungulates', Five things you didn't know about armadillos. 2007. Mesonychids are a mostly Eocene group that originated in the Paleocene; Mesonyx, from the Middle Eocene of North America, was the first member of the group to be named (Cope published the name in . A later genus, Pachyaena, entered North America by the earliest Eocene, where it evolved into species that were at least as large. Archaic ungulates ("Condylarthra"). The early representatives of these groups appeared about 33 million years ago and ultimately gave rise to forms as diverse as the Yangtze River dolphin and the gigantic blue whale. Raoellids likeIndohyuswere the closest relatives to whales, with hippos being the next closest relatives to both groups combined. ? Instead, the density suggests that it walked on the bottom of rivers and lakes like the hippopotamus. homestead high school staff. Journal of Vertebrate Paleontology 15, 855-859. Its skeleton bears no evidence that it could move fast in the water. Mesonychids in North America were by far the largest predatory mammals during the early Paleocene to middle Eocene. Over time, the family evolved foot and leg adaptations for faster running, and jaw adaptations for greater bite force. mesonychids limbs and tailbiblical counseling raleigh, nc | Mesonychid dentition consisted of molars modified to generate vertical shear, thin blade-like lower molars, and carnassial notches, but no true carnassials. In the space of just three decades, a flood of new fossils has filled in the gaps in our knowledge to turn the origin of whales into one of the best-documented examples of large-scale evolutionary change in the fossil record. Mesonychids were not the ancestors of whales, and hippos are now known to be the closest living relatives to whales. When the fossil data was combined with genetic data by Jonathan Geisler and Jennifer Theodor in 2009, a new whale family tree came to light. An unrelated early group of mammalian predators, the creodonts, also had unusually large heads and limbs that traded flexibility for efficiency in running; large head size may be connected to inability to use the feet and claws to help catch and process food, as many modern carnivorans do. This condition is called pachyosteosclerosis, and whales are the only mammals known to have such a heavily thickened involucrum. For this reason, scientists had long believed that mesonychids were the direct ancestor of Cetacea, but the discovery of well-preserved hind limbs of archaic cetaceans, as well as more recent phylogenetic analyses now indicate cetaceans are more closely related to hippopotamids and other artiodactyls than they are to mesonychids, and this result is consistent with many molecular studies. The group of animals that had the most features common to the earliest primitive whales found was called the Mesonychids . > predators might have some credit after all. He had found vertebrae and other fragments while blasting on his property and also sent off a few samples to the Philadelphia society. These forms eventually died out, but not before giving rise to the early representatives of the two groups of whales alive today, the toothed whales and the baleen whales. But, because they are mammals, we know that they must . There is evidence to suggest that some genera were sexually dimorphic. Even more surprising was that comparisons of these proteins used to determine evolutionary relationships often placed whaleswithinthe Artiodactyla as the closest living relatives to hippos. Most paleontologists now doubt that whales are descended from mesonychids, and instead suggest mesonychians are descended from basal ungulates, and that cetaceans are descended from advanced ungulates (Artiodactyla), either deriving from, or sharing a common ancestor with, anthracotheres (the semiaquatic ancestors of hippos). They were probably active hunters. Cetaceans, like many other mammals, have ear bones enclosed in a dome of bone on the underside of their skulls called the auditory bulla. Postcranial skeleton of the early Eocene mesonychid Pachyaena (Mammalia: Mesonychia). Summary written by Jonathan Geisler and Melody Ho. Dissacus was a jackal- or wolf-sized mesonychid that occurred throughout the Northern Hemisphere during the Late Paleocene (more than ten species have been named). Geisler, J. H. 2001. Darwin had done no such thing, but the jeering caused him to modify the passage in subsequent editions of the book. Were there really any distance runners in the paelogene? The fact that it was found in freshwater deposits and did not have specializations of the inner ear for underwater hearing showed that it was still very early in the aquatic transition, and Gingerich and Russell thought ofPakicetusas an amphibious intermediate stage in the transition of whales from land to sea, though they added the caveat that Postcranial remains [bones other than the skull] will provide the best test of this hypothesis. The scientists had every reason to be cautious, but the fact that a transitional whale had been found was so stupendous that full-body reconstructions ofPakicetusappeared in books, magazines and on television. As in most land mammals, the nose was situated at the tip of the snout. mesonychids limbs and tailokinawan sweet potato tempura recipe. But the conflict was not without hope of resolution. Dissacus was a jackal-sized predator that has been found all over the Northern Hemisphere,[3] but species of a closely related or identical genus, Ankalagon, from the early to middle Paleocene of New Mexico, were far larger, growing to the size of a bear. LikeBasilosaurus, though,Squalodonwas fully aquatic and provided few clues as to the specific stock from which whales arose. Nature 361:444-445. The only tail vertebra found is long, making it likely that the tail was also long. 1998. But, long ago, not all ungulates were herbivores. [2] Mesonychids first appeared in the early Palaeocene with the genus Dissacus. Some mesonychids are reconstructed as predatory (comparable to canids), others as scavengers or carnivore-scavengers with bone-crushing adaptations to their teeth (comparable to the large hyenas), and some as omnivorous (comparable to pigs, humans, or black bears). Among other taxa, Pachyaena and Sinonyx appear to be successively more basal relative to the Harpagolestes + Mesonyx clade. They were also most diverse in Asia where they occur in all major Paleocene faunas. This global catastrophe cleared the way for a major radiation of mammals. [5] They would have resembled no group of living animals. Together they illustrate how the entire transition took place. - . The long-snouted and otter-like remingtonocetids appeared next, including small forms like the 46-million-year-oldKutchicetus. The largest species are considered to have been scavengers. These later mesonychids had hooves, one on each toe, with four toes on each foot. Nearly all mesonychids are, on average, larger than most of the Paleocene and Eocene creodonts and miacoid carnivorans. Many of the skeletons of the earliest archaeocetes were extremely fragmentary, and they were often missing the bones of the ankle and foot. Clarendon Press (Oxford), pp. Writing to his staunch advocate T.H. Inside Nature's Giants: a major television event worthy of praise and accolade. Mammals diversified in the shadow of the great archosaurs, and they remained fairly small and secretive until the non-avian dinosaurs were wiped out by a mass extinction 65 million years ago. Looking at those mesonychid skulls and comparing them to *Andrewsarchus*, I begin to wonder why the latter is usually considered one of the former anyway. Thus it is unclear if it was an active predator or if instead it ambushed unsuspecting prey that wandered too closely. While later mesonychids evolved a suite of limb adaptations for running similar to those in both wolves and deer, their legs remained comparatively thick. Please make a tax-deductible donation if you value independent science communication, collaboration, participation, and open access. About 375 million years ago, the first tetrapodsvertebrates with arms and legspushed themselves out of the swamps and began to live on land. 1995. Pakicetus had a long snout; a typical complement of teeth that included incisors, canines, premolars, and molars; a distinct and flexible neck; and a very long and robust tail. Compared to what we're used to in modern mammals, it also seems that mesonychids would have looked big-headed and also long-necked. Learn Mesonychid facts for kids. The foot was compressed for efficient running with the axis between the third and fourth toes (paraxonic); it would have looked something like a hoofed paw. Terms of Use The only tail vertebra found is long, making it likely that the tail was also long. The hypothesis that Ambulocetus lived an aquatic life is also supported by evidence from stratigraphy Ambulocetus's fossils were recovered from sediments that probably comprised an ancient estuary and from the isotopes of oxygen in its bones. can general dentists do bone grafts; apple tartlets with pillsbury pie crust; what bulbs will squirrels not eat; can cinnamon cause a miscarriage; mesonychids limbs and tail. If the early ancestors of whales had large, broad tails, that could explain why they evolved such a unique mode of swimming. Once they had begun swimming for their supper, succeeding generations would become more and more aquatically adapted until something as monstrous as a whale evolved. Beginning in 1983, paleontologists have. Finally, the cheek teeth were not as sharp, or an enlarged, as those of canids and other predatory carnivorans, so mesonychids were apparently less good at slicing through tissue. It was thick and highly mineralized, just like the bone in whale ears. Cookie Settings. Critics took it to mean he was proposing that bears were direct ancestors of whales. It had a long muzzle, teeth that were very similar to later archaeocetes, a reduced . Forgot to say great post! as compared with mesonychids. In Janis, C. M., Scott, K. M. & Jacobs, L. L. (eds) Evolution of Tertiary Mammals of North America. The phylogeny of the ungulates. Mesonychia ("middle claws") is an extinct taxon of small- to large-sized carnivorous ungulates related to artiodactyls. They were endemic to North America and Eurasia during the Early Paleocene to the Early Oligocene, and were the earliest group of large carnivorous mammals in Asia.They are not closely related to any living mammals. Glad you tooted. Unlike all modern and possibly all other fossil cetaceans, it had four fully functional, long legs. He'll find her! Szalay, F. S. & Gould, S. J. [3], The mesonychids were an unusual group of condylarths with a specialized dentition featuring tri-cuspid upper molars and high-crowned lower molars with shearing surfaces. In some localities, multiple species or genera coexisted in different ecological niches. A typical example of these animals (e.g. Copyright 2010. Together these fossil whales hung in a kind of scientific limbo, waiting for some future discovery to connect them with their land-dwelling ancestors. Mesonychids probably originated in China, where the most primitive mesonychid, Yangtanglestes, is known from the early Paleocene. Riley Black is a freelance science writer specializing in evolution, paleontology and natural history who blogs regularly for Scientific American. These "wolves on hooves" are an extinct order of carnivorous mammals, closely related to artiodactyls.. Mesonychids first appeared in the early Palaeocene with the genus Dissacus.They went in decline at the end of the Eocene, and became extinct in the early Oligocene. Based on this, Pakicetus retained the ability to hear airborne sound. They would have resembled no group of living animals. whales came to be after millions of years of evolution. While analyzing the relationships of ancient meat-eating mammals in 1966, however, the evolutionary biologist Leigh Van Valen was struck by the similarities between an extinct group of land-dwelling carnivores called mesonychids and the earliest known whales. All our content comes from Wikipedia and under the Creative Commons Attribution-ShareAlike License. New morphological evidence for the phylogeny of Artiodactyla, Cetacea, and Mesonychidae. Journal of Paleontology 81:176-200. [4] A later genus, Pachyaena, entered North America by the earliest Eocene, where it evolved into species that were at least as large. - . Who says that the solution adopted by carnivorans, dasyurids, sparassodonts and "creodonts" - basal cynodont dentition + carnassials - is the best or the only solution for processing meat? Upload your study docs or become a member. For previous articles on Paleogene mammals see And for other stuff on neat and obscure fossil mammals see Archibald, J. D. 1998. As strange as modern whales are, their fossil predecessors were even stranger. 1966. But while preparing the sixth edition, he decided to include a small note aboutBasilosaurus. Since other predators, such as creodonts and Carnivora, were either rare or absent in these animal communities, mesonychids most likely dominated the large predator niche in the Paleocene of eastern Asia. A recent study found mesonychians to be basal euungulates most closely related to the "arctocyonids" Mimotricentes, Deuterogonodon and Chriacus. [12] However, the close grouping of whales with hippopotami in cladistic analyses only surfaces following the deletion of Andrewsarchus, which has often been included within the mesonychids. | READ MORE. If ancient omnivorous ungulates could eventually be found, Flower reasoned, it would be likely that at least some would be good candidates for early whale ancestors. And another matter, given that mesonychian meat processing really didn't seem to be up to snuff, compared to modern carnivorans, their traditional characterisation as archaic,'inferior' predators might have some credit after all. If blue whales built statues to each other theyd be smaller then these.Simon Hoggart (b. American black bear, with a long stout tail, and a wide head as large as that of a grizzly bear. However, they also found Dissacus to be paraphyletic with respect to other mesonychids, so further study and perhaps some taxonomic revision is needed [Greg Paul's reconstruction of Ankalagon shown in adjacent image]. Part I! Discuss with your teammates what traits you would expect to find (in the head , limbs , tail , . Functional and behavioral implications of vertebral structure in Pachyaena ossifraga (Mammalia, Mesonychia). Hippopotamus and whale phylogeny. Triisodontidae. The molars have steeply inclined wear facets that formed when the upper and lower teeth contacted during chewing. Nearly all mesonychids are, on average, larger than most of the Paleocene and Eocene creodonts and miacoid carnivorans. Which were more reliable, teeth or genes? For this reason, scientists had long believed that mesonychids were the direct ancestor of Cetacea, but the discovery of well-preserved hind limbs of archaic cetaceans, as . References Consulted: While the limb proportions and hoof-like phalanges indicate cursoriality, the limbs were relatively stout and show that it cannot have been a long-distance pursuit runner. The bulla was in turn connected to the chain of middle ear bones (i.e. (ed) The Phylogeny and Classification of the Tetrapods, Volume 2: Mammals. Unlike all modern and possibly all other fossil cetaceans, it had four fully functional, long legs. Even in so extreme a case as this, if the supply of insects were constant, and if better adapted competitors did not already exist in the country, I can see no difficulty in a race of bears being rendered, by natural selection, more and more aquatic in their structure and habits, with larger and larger mouths, till a creature was produced as monstrous as a whale. The postcranial skeleton of early Eocene pakicetid cetaceans. It was assigned to Creodonta by Cope (1880); to Creodonta by Cope (1889); to Carnivora by Peterson (1919); to Mesonychia by Carroll (1988) and Zhou et al. -Kyle Reese, the Terminator Thus the thickened bulla of Pakicetus is interpreted as a specialization for hearing underwater sound. 2006-2020 Science 2.0. With a short lower spine stiffened by revolute joints, they would have run with stiff backs like modern ungulates rather than bounding or loping with flexible spines like modern Carnivorans. But, because they are mammals, we know that they must have evolved from land-dwelling ancestors. They were major predators in the Northern Hemisphere from shortly after the demise of the dinosaurs until about 30 million years ago, and the shape of their teeth resembled those of whales likeProtocetus. 133-161. A recent study found mesonychians to be basal euungulates most closely related to the "arctocyonids" Mimotricentes, Deuterogonodon and Chriacus. In Asia, the record of their history suggests they grew gradually larger and more predatory over time, then shifted to scavenging and bone-crushing lifestyles before the group became extinct. However, it had rather short, strong hind limbs, with huge feet (each toe with a tiny mesonychid-type hoof!). 2008. 2006. 24 Jun . We use cookies to see how our website is performing. Journal of Vertebrate Paleontology 15, 401-430. Yep, you are correct - a stupid error that I will now go correct, thanks. In C. M. Janis, K. M. Scott, and L. L. Jacobs (eds. Adult fish, chickens, dogs, and lizards don't look much like humans. Such muscles are consistent with webbed feet that were used for aquatic locomotion. There don't seem to be very many reconstructions of these critters available online.http://viergacht.deviantart.com/art/Harpagolestes-133779748, Very nice, Viergacht! It had slender jaws and narrow teeth, and on account of these has sometimes been suggested to be piscivorous. Parsimony analysis of total evidence from extinct and extant taxa and the cetacean-artiodactyl question (Mammalia, Ungulata). Richard Owen, a rising star in the academic community, carefully scrutinized every bone, and he even received permission to slice into the teeth to study their microscopic structure. 1946). In some localities, multiple species or genera coexisted in different ecological niches. A startling discovery made in the arid sands of Pakistan announced by University of Michigan paleontologists Philip Gingerich and Donald Russell in 1981 finally delivered the transitional form scientists had been hoping for. Journal of Vertebrate Paleontology 26:355-370. They were also most diverse in Asia, where they occur in all major Paleocene faunas. Mesonychids first appeared in the early Paleocene, went into a sharp decline at the end of the Eocene, and died out entirely when the last genus, Mongolestes, became extinct in the early Oligocene. spy wednesday images pitt law grade distribution mesonychids limbs and tail. Huxley replied that there could be little doubt thatBasilosaurusprovided clues as to the ancestry of whales. Yantanglestes from Paleocene Asia (originally described as a species of Dissacus) is also thought to be a basal member of the group. This whale has been found at several localities in the Punjab and North-West Frontier provinces of Pakistan. I think the prezygapophyses and postzygapophyses are incorrectly identified in the essay. The molars were laterally compressed and often blunt and were probably used for shearing meat or crushing bones. Adapted fromWritten in Stone: Evolution, the Fossil Record, and Our Place in Nature, by Brian Switek. Advertising Notice The two most basal taxa are Dissacus and Ankalagon (Archibald 1998, O'Leary 1999, 2001, Geisler & McKenna 2007). Technically speaking, the term "mesonychid" refers specifically only to the members of the family Mesonychidae, such as the species of the genus Mesonyx. Harlan traveled to London in 1839 to present Basilosaurus to some of the leading paleontologists and anatomists of the day. Based on the skull sizes of Pakicetus specimens, and to a lesser extent on composite skeletons, species of Pakicetus are thought to have been 1 to 2 meters in length (4 to 5 feet). Mesonychids first appeared in the early Paleocene, went into a sharp decline at the end of the Eocene, and died out entirely when the last genus, Mongolestes, became extinct in the early Oligocene. Mesonychians were long considered to be creodonts, but have now been removed from that order and placed in three families (Mesonychidae, Hapalodectidae, and Triisodontidae), either within their own order, Mesonychia, or within the order Condylarthra as part of the cohort or superorder Laurasiatheria. Looking back at it now, that very first ver 2 post is rather odd. The current uncertainty may, in part, reflect the fragmentary nature of the remains of some crucial fossil taxa, such as Andrewsarchus. 1981. (1995) found Mongolonyx and Mongolestes (both from Eocene Asia) to be part of this clade as well. That's what he does! In artiodactyls this bone has an immediately recognizable double pulley shape, a characteristic mesonychids did not share. The bulla is the bone of the skull that formed the floor of a cavity that housed the middle ear ossicles (the malleus, incus, and stapes). A million years later livedAmbulocetus, an early whale with a crocodile-like skull and large webbed feet. "Triisodontidae" may be paraphyletic. No one quite knew what to make of them. The earliest known archaeocetes were creatures like the 53-million-year-oldPakicetusand the slightly olderHimalayacetus. The American Phrenological Journal and Miscellany, Vol. Pachyaena is reasonably well-known (Zhou et al. It is my understanding that most of the world was more forested, with far less open grassland than there is now. This idea was contested by O'Leary (1998), however, and it's mostly agreed that, while Dissacus is a basal mesonychid, Hapalodectes is a member of another mesonychian clade that we'll be looking at later on. Our inability to find limbs and tails was so frustrating that in 2000 we moved from this area, where fossil-bearing strata are beautifully exposed, to the west side of the Sulaiman Range in Balochistan Province. This conflict makes his soul a battlefield, where the forces that wish this reconciliation fight those that do not and reject the alternative solutions they offer. As described in the comments above, all known skeletons of Pakicetus are composites created by gathering isolated bones. Well-developed puncturing cusps (incisors) and serrated cheek teeth indicate that Pakicetus ate flesh, most likely that of fish. Mesonychidae Pachyaena Pakicetus Ambulocetus Rodhocetus Basilosaurus Zygorhiza Year reported Country where found Geological age (mya) Habitat (land, fresh water, shallow sea, open ocean) Skull, teeth, ear structure types most like. Image credit: NASA / Apollo 17. The skull ofPakicetusexhibited just this condition. (1988) to name a new clade, Hapalodectini, which they regarded as the sister-taxon to a (mesonychid + (Andrewsarchus + cetacean)) clade (that's right, they regarded Andrewsarchus as the sister-taxon to Cetacea). The phylogenetic position of cetaceans: further combined data analyses, comparisons with the stratigraphic record and a discussion of character optimization. [2] Some researchers now consider the family a sister group either to whales or to artiodactyls, close relatives rather than direct ancestors. From Fowler, O.S. & Geisler, J. H. 1999. Mesonychids in North America were by far the largest predatory mammals during the early Paleocene to middle Eocene. Mesonychid taxonomy has long been disputed and they have captured . It had limbs like a land animal and webbed toes in replacement for fins, suggesting that it recently changed from land to water through evolution. New York: Fowler & Wells. Like the Paleocene family Arctocyonidae, mesonychids were once viewed as primitive carnivorans, and the diet of most genera probably included meat or fish. The position of Cetacea within Mammalia: phylogenetic analysis of morphological data from extinct and extant taxa. So why do these embryos look so much alike? Brys donation was soon matched, and even exceeded, by that of Judge John Creagh from Alabama. Phylogenetic and morphometric reassessment of the dental evidence for a mesonychian and cetacean clade. . By continuing to use the website, you consent to analytics tracking per NYIT's Privacy Statement In the meantime, scientists speculated about what the ancestors of whales might have been like. Archaeocetes had a double-pulley astragalus, confirming that cetaceans had evolved from artiodactyls. They are all placed in the order Cetartiodactyla alongside terrestrial even-toed ungulates (hoofed mammals). It was only about 10 million years after this extinctionand more than 250 million years since the earliest tetrapods crawled out onto landthat the first whales evolved. Cookie Policy On January 23rd 2007, Tet Zoo ver 2 - the ScienceBlogs version of Tetrapod Zoology - graced the intertoobz for the first time. queen of the south why did javier kill tony. The molars were laterally compressed and often blunt, and were probably used for shearing meat or crushing bones. However, even though they are similar in appearance to land animals, some consider Mesonychids to be ancestors of whales. Your Privacy Rights Pakicetus has not been found from deposits of the Tethys Sea but instead from adjacent river and floodplain deposits, which also yield bones of land dwelling mammals. When the genes and amino acid sequences of living whales were compared with those of other mammals, the results often showed that whales were most closely related to artiodactylseven-toed ungulates like antelope, pigs, and deer. Theropods, several crurotarsan clades and, to a certain degree, even entelodonts did just fine with ziphodont teeth; Australia's top mammalian predator wasn't a dasyurid, but *Thylacoleo*. Volume 1: Terrestrial Carnivores, Ungulates, and Ungulatelike Mammals. However, recent work indicates that Pachyaena is paraphyletic (Geisler & McKenna 2007), with P. ossifraga being closer to Synoplotherium, Harpagolestes and Mesonyx than to P. gigantea. Accept Cookies, Osteopathic Manipulative Medicine Research. Although they share a common ancestor, the Carnivora are split into two quite well-defined groups that are broadly dog-like, the . An unrelated early group of mammalian predators, the creodonts, also had unusually large heads and limbs that traded flexibility for efficiency in running; large head size may be connected to inability to use the feet and claws to help catch and process food, as many modern carnivorans do. Sensory Abilities: In fact, the density of the limb bones of Pakicetus is so great that they would have been at increased risk of breakage during running. While preparing the underside of the skull ofIndohyus, a student in Thewissens lab broke off the section covering the inner ear. Thewissen, J. G. M., Cooper, L. N., Clementz, M. T., Bajpai, S. & Tiwari, B. N. 2007. However, as the order is also renamed for Mesonyx, the term "mesonychid" is now used to refer to members of the entire order Mesonychia and the species of other families within it. Limbs and tail: Description; Did it swim? They are not closely related to any living mammals. Mesonychids exemplified a wide variety of appearances, ranging from those similar to wolves, hyenas, bears, and dogs (Jehle 2010). Recent fossil discoveries have overturned this idea; the consensus is that whales are highly derived artiodactyls. Richard Harlan reviewed the fossils, which were unlike any he had seen before. An introduction to evolution: what is evolution and how does it work? They were endemic to North America and Eurasia during the Early Paleocene to the Early Oligocene, and were the earliest group of large carnivorous mammals in Asia. 3 0 obj << /Linearized 1 /O 5 /H [ 677 158 ] /L 5375 /E 5050 /N 1 /T 5198 >> endobj xref 3 14 0000000016 00000 n 0000000624 00000 n 0000000835 00000 n 0000000988 00000 n 0000001184 00000 n 0000001289 00000 n 0000001393 00000 n 0000001499 00000 n 0000001552 00000 n 0000002666 00000 n 0000003413 00000 n 0000004908 00000 n 0000000677 00000 n 0000000815 00000 n trailer << /Size 17 /Info 2 0 R /Root 4 0 R /Prev 5189 /ID[<4e5292bec552ff6cdecba3d79dd8a517><4e5292bec552ff6cdecba3d79dd8a517>] >> startxref 0 %%EOF 4 0 obj << /Type /Catalog /Pages 1 0 R >> endobj 15 0 obj << /S 36 /Filter /FlateDecode /Length 16 0 R >> stream [13], This article is about the prehistoric ungulate. Throughout the 1990s, the skeletons of more or less aquatically adapted ancient whales, or archaeocetes, were discovered at a dizzying pace. Invasion of the marsupial weasels, dogs, cats and bears or is it? fc alliance soccer club knoxville tn. Harlan thought the bones were most similar to those of extinct marine reptiles such as the long-necked plesiosaurs and streamlined ichthyosaurs.