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A small , furry fauna with a blunt snout and beady eyes scuttled across what is now eastern Utah some 130 million years ago . And while the teensy beast was surely unusual and enchanting , there ’s one matter it was definitely not : half - mammal and half - reptilian .
headline about the recent find have described it as though it were some outlandish hybrid of reptilian and mammal . But while it might be funny to ideate a beast with the front end of a lizard and the rearward end of a scum bag , it ’s not very scientific . [ Real or Fake ? 8 Bizarre Hybrid Animals ]
Cifelliodon wahkarmoosuch lived during the Cretaceous period and belonged to a group that was closely related to mammals.
The small brute , which would have stood just 3 inches ( 7.6 centimeters ) tall and weigh about 2.5 pounds ( 1.1 kilograms ) , belong to a grouping known as the haramiyidans , which emerge during the lateTriassic period(251 million to 199 million years ago ) , and are know mostly from fossil teeth . scientist have argued over whether haramiyidans were early mammalian or a sister group — close related to mammals , but lacking some characteristic used by paleontologists to decide who ’s a mammal and who ’s not .
In a raw survey name the tiny skull — which represents a new genus and specie of haramiyidan calledCifelliodon wahkarmoosuch , and is thought to be between 139 million and 124 million years old — researcher fix that haramiyidans were mammal relatives , though not genuine mammals . And though haramiyidans looked a lot like mammalian , they retained more " nonmammalian " structures from their aloof ancestors than the first dependable mammal did , the scientist account . [ Image Gallery : 25 Amazing Ancient Beasts ]
Both haramiyidans and mammals trace their line of descent to a group known as the synapsid . All syanpsids last shared a common ancestor with reptile about 330 million years ago , " so the split between reptile and mammal runs very deep , " paleontologist Elsa Panciroli , who was not involved in the newfangled study , told Live Science in an e-mail .
In other Holy Writ — mammals do n’t have " reptile ancestors . " Rather , both mammal ancestor and reptile ancestor branched off from a shared unwashed ancestor hundreds of million of years ago , Panciroli explained .
In the yesteryear , scientist might have say that former synapsids shared more features in vulgar with reptiles than with mammals , " but really we need to bet at it as being more about which group is more like their common root , " said Panciroli , a doctoral candidate study mammal origins at the University of Edinburgh and National Museums Scotland .
One trait get hold in reptiles and keep on in some mod mammals isegg - laying , consider inplatypusesand setose anteaters . Egg - laying can be traced back to very distant antecedent of the reptilian and mammal lineages . mammalian with placentas , on the other hand , are think to initiate from a shrew - like brute calledJuramaia sinensis , which hold out about 160 million year ago .
A transitional skull
In life , the newly describedCifelliodoncertainly resembled a mammalian . It had a furry body and a farseeing tail , tooth that could slit and crush flora and lilliputian eye sockets that suggested its eyes were little and its visual sense was hapless . However , its olfactory bulb were unusually large , hinting that it bank heavily on its sense of smell , allot to the study .
High - resolution ex - re scans also revealed the inner cranium shape , which was " transitional between earlier stem mammals and crown Mammalia , " the researcher write . This mean thatCifelliodon — and other haramiyidans — had some mammal - corresponding features , but not as many as the group that defines mammal alive today .
The exceptional condition of theCifelliodonskull — peculiarly its 3D form — extend clues about the haramiyidan group that had only been guessed at before , when the only available fossils were scanty or crushed flat , lead field of study author Adam Huttenlocker , an assistant prof of clinical consolidative anatomical sciences with the Keck School of Medicine at the University of Southern California , toldUSC News .
" The three - dimensional preservation ofCifelliodonhighlights the primitive brain , roof of the mouth and give structure of this special group and reenforce their position near the base of the mammalian family tree , " Huttenlocker enjoin .
The findings were publish online May 23 in the journalNature .
Original article onLive Science .
