Lecture 80 Meat Eating Mammals: Creodonts and Carnivores

welcome to Utah State University's vertebrate paleontology course my name is Benjamin Berger by the end of this video you will be able to arrange the various groups of carnivorous mammals onto a geological time scale showing the extent of each groups fossil record after the extinction of the dinosaurs at the end of the cretaceous mammals quickly diversified into larger herbivore mammals that we've previously discussed but they also diversified into carnivorous mammals these are mammals that have a diet that contains a larger amount of meat principally eating other mammals so today most carnivorous mammals belong in a single group called Carnivora but there were other prehistoric meat-eating mammals that we'll discuss in this video to differentiate the various extinct carnivorous mammals we just have to look at their teeth in particular the placement of carnassial teeth carnassial teeth are sharp teeth which are used for slicing meat and tendons and they have independently evolved in each group and this independent origin explains the various groupings two of the major groups are the Kriya danse isn't an extinct group and the Carnivora these are the modern carnivorous mammals in kriya Dawn's the carnassial teeth are composed of either the lower three molars or the lower second molar while in Carnivora the carnassial teeth is limited to the lower first molar in addition to Kriya dance in carnivores we also have the carnivorous Mezen nickens which are more closely related to artiodactyls and they appear to be like large Pig like carnivores these meat-eating mammals had rows of carnassial teeth which involved into crushing massive teeth late in their evolution all right so let's look at the earliest members of each of these three groups in the Paleo scene in the first three carnivorous mammals living in the new air after the extinction of the dinosaurs among the Carnivora we have protic tiss which has a large lower first molar as the sole carnassial teeth with kriya dontoh we have tahina which has multiple carnassial teeth with meza Nick a day we have die discus with a row of multiple sharp teeth that are now somewhat carnassial in nature but are more a simple kind of scissor-like teeth now all of these Policing carnivores are about coyote or smaller size by the Eocene here in North America carnivorous mammals got larger they got to be about the size of a wolf the top two carnivores display carnassial teeth that involve the upper fourth premolar and the lower first molar this is what is found in cats and dogs today and i Medicus and my asus are more closely related to cats and dogs the lower figured Eocene mammals are hyena dawn in which the upper second third and fourth premolar as well as the entire lower molars are all carnassial teeth this defines a group of kriya daunt mammals called a hyena dawn today while the Eocene mammals on the lower right in the figure is Aqsa Hina which is also a kriya dot but exhibits a car nacio occlusion between the upper first molar and the second lower molar this mammal is a oxy heated kriya don't Aqsa Hena de cría dance were large lion sized mammals that live during the early Eocene and which are well-known in the American West but are also found in Asia and in Europe they had very short skulls that somewhat resembled the skulls of modern big cats some of the coolest oxy canid is Patra felis which is known from the middle eocene bridger formation of southwestern Wyoming it's known from some nearly complete skeletons living also during the early Eocene were the smaller hyena Adhan today which unlike the Aqsa he nodes had multiple carnassial teeth the Heine daunted had longer skulls and were weasel to small dog sized mammals some with the ability to climb trees some of the larger ones during the middle EA scene include sign oppa and pro Lim de sion then around 46 million years ago the larger lion size oxy Heenan swear went extinct and by around 38 million years ago the bear size Meza new kids went extinct which meant that during the last few million years of the Eocene large mammal carnivores were replaced by the hyena daunted which went from weasel sized mammals to large wolf sized mammals like the Lea Eocene hyena daunted a crea daunt hyena Don hyena Don was the climax predator during the late eocene and also represents one of the last of the hyena daunted z-- to exist before their extinction at the end of the Eocene the Eocene Oligocene boundary was important because while many carnivores live through this event the credence finally succumbed to extinction the carnivory survived these survivors would evolve into cats dogs Bay weasels pinnipeds and hyenas among the Eocene Carnivora were a group called the my asa day which closely resembled small dogs or coyotes some of which were arboreal while others were more terrestrial the other group of Eocene Carnivora were the viv arreva de which were civet like mammals for many years the viverridae were placed in the philia forma this is a large branch that would lead to cats while the my ASA day were placed into the cana for Mia as ancestors to dogs this the dog cat split in evolution occurred early within the group however more recent work has argued that the vivir Ava day and my ASA day are really splits early splits off the tree and are not ancestral to either cats or dogs and are not even grouped within Carnivora they're grouped in a larger grouping called the Carnivora morphs you know some of the my ace a day are closely related to Carnivora like tap a scion this is a middle eocene carnivorous mammal known from here in Utah so in this new scheme the first true Carnivora are the early can of forma Hesperus ion now Hesperus ion is from the Lea scene of Colorado which was a fox like carnivore now there's one other group that shows up at the end of the Eocene called the NIM revit a which are known also as the false saber-toothed cats they have many cat-like features like retractable claws and saber like teeth and the most well-known is Hopi F Onis from the White River Formation of Colorado these early saber-tooth cats lived at the end of the Eocene and are the sister group to the crown branch of Carnivora we'll see the evolution of Sabre teeth twice as later on within the cat family they will appear again from the legacy to modern epochs two groups would remain the first group the Fila forma includes four families the felidae the cats the very day the civets the hurt pest today the mongooses and the hyena day the hyenas true saber-toothed cats would evolve in the Pliocene in Plaistow scene and are closely related to lions panthers and mountain lions as well as house cats the most famous of the true saber-toothed cats is Smilodon known from hundreds of skeletons from los angeles from the liya Brea Tar Pits locality near Hollywood so why did long saber-toothed mammals appear to evolve multiple times well one theory is that these long saber teeth were an effective tool for subduing larger prey like when a big cat tries to take down a larger hoofed mammal it risks getting kicked to death or stabbed with nasty horns so the cat goes after the vital organs in the throat including the carotid blood vessels knocking out brain function as well as the trachea which quickly disrupts airflow into the lungs a ripping out throat is one way to knock down a larger predator and hence feed the family for a longer period of time then carnivores that have to hunt smaller prey the other group of a legacy to modern carnivores includes the Cana Pharma these include the canid family the modern dogs as well as a group called the octo today which includes bears bear dogs seals and walruses as well as diverse Mustela day the skunks raccoons weasels and otters and fossils from this group are impressive the cave bears are found across Europe from the Late Pleistocene living alongside humans in Europe during the Ice Age bear dogs live during the Maya scene and where large ground adapted bear like mammals with massive skulls pinniped a the group that would evolve into seals and walruses have a fossil record extending into the early Maya scene and are the newest group of mammals to make this shift into the marine environment as fully aquatic mammals although they spend many hours on the coastlines alright so we've covered a lot of groups so let's look at how long these meat-eating mammals live by looking at their stratigraphic record the Meza nekkid a live during the Paleocene and Eocene the credence are really two groups the hyena Don today which lived during the Paleocene and Eocene while the Aqsa he today lived during the Paleocene in only the first half of the Eocene the my asa day in viv arreva day lived during the Paleocene and Eocene while the saber-tooth Nimrod a appear at the end of the Eocene and lived into the Maya scene the Felidae and relatives appear at the early illega scene and survived to the present while the kanaday and relatives appear in the late eocene and survived to the present the Bears Ursula appeared during the Oligocene while the Ann frisina Don the bear dogs appear at the base of the alig Essene although a recent discovery suggests in middle eocene origin for the group while the Penev headed a the seals and Rama's appear in the early Maya scene so this is the arrangement of the various groups of carnivorous mammals on a geological time scale showing the extent of each groups fossil record I hope that you've learned something cool about meat-eating mammals in this video thank you for watching if you'd like to learn more about Utah State University's geology program check out the website geology USU edu or my own website benjamin slash burger org links are found in the description below

Channel: Benjamin Burger

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Keywords: creodonts, carnivores, meateaters, paleontology, vertebrate paleontology, mammals, lectures, lessons, education, evolution, science, college lecture

Id: Nol3cetTwtI

Length: 13min 44sec (824 seconds)

Published: Mon Nov 28 2016