The Ancient ‘Mammals’ that Reigned Before the Dinosaurs

for some people when they think of what animals dominated land habitats before the dinosaurs they might think of giant insects or maybe large squatting amphibians but stretching about 18 million years before the dinosaurs took over the world the dominating creatures were actually ancestors of mammals and their relatives about 340 million years ago during a period known as the Carboniferous land vertebrates were represented by small lizard looking animals they had moved away from their fish like ancestors in evolving the appropriate adaptations to take up permanent residence on the land mainly in adapting amniotic eggs they could be laid on the land meaning they were no longer tied to the water very early on these massive land creatures the version to three distinct groups there were signed out it's an absence and die opposites all categorized by the amount of holes in ESCO an abscess had none synapses had one and died opposites had two the absence would go on to become reptile shortly after the split and then eventually birds and dinosaurs the consensus is that announcers have no currently living representatives although some scientists have argued that turtles are in fact in opposites that this is a controversial theory finally synapses contain all living mammals and all their extinct relatives although they would be barely recognizable as mammals at this point in history right from the start of the Permian period 300 million years ago it was the synapses that were becoming the dominant land creatures and reptiles would have to wait one of the earliest large line APS's was a very strange-looking creature would coat of their incus that had an almost comically tiny head for its body size and this was not the only way looking early synapses as there was also a stem asuka's that had large horns coming from its face not too dissimilar to antlers although the most unquestionably famous early side nap said was Dimetrodon the different species of Dimetrodon varied in size a lot but the largest may have been almost 5 metres meaning it was probably the largest predator around at this time it possessed a sail running down its back along with quite a few other sign apps it's from this time record on to Saurus and add a thesaurus the early permian most likely had a very similar climate to the current day so it was thought that these sales may have been used for thermoregulation as it would have been pretty cold in the winter and a lot of these habitats Dimetrodon were far more closely related to you than their wives of dinosaurs but with their reptilian appearance and probable cold-bloodedness you could be forgiven for not seeing it however Dimetrodon were early sign ups its and later they would start to become much more mammalian the more mammalian descendants are referred to as the rhapsode and these animals started to out-compete the early sign apses like Dimetrodon in the mid Permian less talked about the defining feature of mammals unique among the animal kingdom's are their ear bones unlike all other animals mammals have three bones that aid in the function of their ears reptiles only possess one bone in their ear but their jaws are much more complicated with many bones early so an abscess also had complex multiple bone jaws and over the course of the evolution of spine APS's these bones started to ride further and further back until eventually forming the ear bones an early species of mammal this change in your placement is so indicative of the evolution of these mammal ancestors that it's often used to gauge how closely related a synapse it is to a true mammal moving down the synaptic family tree closer to true mammals you would find groups of animals like gorgonopsids stem mammals breaking away from the mammal lineage before they became mammals but they still have many mammalian features the jaw and ear bone was starting to look a lot more mammal-like and their hind legs were directly beneath them unlike with reptiles the largest species was the size of a bear and they were ferocious carnivores tearing into flesh with their saber teeth however there was a lot more to their teeth than just this they were some of the first animals to evolve what is called a hetero bot where their teeth of several different shapes of doing different jobs but by far the most amazing thing about these animals is that they possess some fur covering it is not thought that they were completely covered in fur but they had found some fossilized feces with hair in it from the time period thoughts are belong to a Gorgon opposite the largest mass extinction in history hit the earth at the end of the Permian 250 million years ago and along with nearly all other life on Earth the majority of sign APS's were killed including the Gorgon options the end of the mass extinction marks the beginning of the Triassic period and despite the devastation surely after synapses was still the dominant group of animals with Lister Soros having a short-lived but massive success right at the beginning of the Triassic during the Triassic the climate was much hotter and drier than the Permian and this is when you start to see a previously obscure reptile known as arca sores start to gain a foothold basilar castles are the ancestors of crocodiles and dinosaurs and they seem to have been better suited for the new environment although arca sores were becoming more and more common in diversifying the group of sign abscess that included Lister Soros called dissonance still dominated large herbivore niches even after the appearance of the dinosaurs they coexisted with the dinosaurs for about 30 million years and perhaps even co-evolved as towards the end of their existence they grew to very large sizes the largest and lastest immigrant was called Lisa Whittier and was a size of an African elephant and died out 200 million years ago the ancestor of sauropods replaced them as the dominant herbivores sign absence would not be the dominant animals again until the extinction of the dinosaurs descendants weren't close relations of mammals but actually branched off longer ago than korkin options the representatives of the mammal ancestral lineage during the Triassic with the Bassel members of a group called signer Don Tia there contains all living mammals their ancestors and their closest relatives their close relatives would contain animals like try a record on there was a burrowing animal a multi-chambered burro was found from the Early Triassic containing 20 skeletons of this animal this is the earliest evidence of cohabitation in burrows and shows a level of social sophistication previously thought to be unique to primitive mammals Saladin's like these had marks in their upper and lower jaw which is what you see with animals that have whiskers and a litter all this they were also partially warm-blooded but not to the same extent as mammals artists depictions often show them with fur and although this is perfectly valid conjecture there is currently no evidence of this direct evidence for complete fur coverings and synapsis did not turn up until 205 million years ago in mammalian forms which at this point in history was small rodent like animals that would eventually become true mammals during the Jurassic although the end of the Triassic marked the end of their dominance one group of non-mammalian synapses caught trettel on today survived right up into the Early Cretaceous as little as 110 million years ago thank you for watching if you'd like to be notified of future uploads for me then consider subscribing [Music]

Channel: Moth Light Media

Views: 1,509,615

Keywords: Mammal evolution, reptile to mammal evolution, cute mammal, primitive mammal, mammalsbeofre the dinosaurs, life before the dinosaurs, dinosaurs, grogonopsids, diapsids, synapsids, anapsids, turtles, cynodonts, dicynodonts, paleo, paleontology, evolution, synapsid and diapsid

Id: hO5N70tUfvM

Length: 7min 5sec (425 seconds)

Published: Mon Apr 08 2019