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An unknown dodo collected more than three decade ago was really a mysterious specie of cavalry sword - toothedcarnivorethat once stalked prey through the ancient rainforests of Southern California .
The fossil include a near - gross lower jawbone and a set of well - preservedteeth , according to a unexampled discipline , put out Tuesday ( March 15 ) in the journalPeerJ. Paleontologists at the San Diego Natural History Museum ( The Nat ) earlier collected the specimen in 1988 from a site known as the Santiago Formation in Oceanside , a city in San Diego County , California . The geological formation is estimated to be about 42 million years old , so dodo from the land site date back to the Eocene era ( 55.8 million to 33.9 million years ago ) , accord to theAmerican Museum of Natural History .
A newly named species of hypercarnivore lived during the Eocene and is not not closely related to any living carnivores.
When the fossilized mandible was ab initio discovered , " it had been very properly identify as a nub - feed animal , " said study co - author Ashley Poust , a postdoctoral researcher in vertebrate palaeontology at the Nat . The specimen bears " openhanded , fade , scissoring dentition " that are ideally beseem for shred fresh meat , rather than for crunching through loony or gnawing onbones , for example , Poust said .
The museum palaeontologist originally thought these formidable teeth might belong to a nimravid , a type of Caterpillar - similar hypercarnivore , an beast whose diet consisted mostly of meat . The nimravids are often called " false saber - toothed cats , " as they resemble the famous feline but do n’t go to the Felidae crime syndicate as true big cat do , Live Science previously reported .
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This fossil has been in The Nat’s collection since 1988. It was recovered in Oceanside by the museum’s PaleoServices team.
However , study co - generator Hugh Wagner , a paleontologist at the Nat , later suggested that the mandibula might belong to to a more cryptic radical of hypercarnivores with light representation in the fossil phonograph recording : the machaeroidines . corpse of these unusual animate being have been uncover only at select sites in Asia and North America , and prior to the raw study , only 14 specimen had ever been find , according to the PeerJ report . The now - extinct group includes the earliest known sabre - toothed mammalian carnivores , which are not intimately related to any living carnivores .
Two of these specimens — a fond skeleton and a jawbone — were unwrap in Wyoming and Utah and delineate inpriorpapersby the study ’s co - first writer Shawn Zack , an adjunct prof at the University of Arizona College of Medicine and an expert in ancient carnivores . For the newfangled report , Zack , Poust and Wagner team up up to review the perplexing carnivore jawbone in the Nat ’s ingathering and determine , once and for all , whether it belong to to a machaeroidine .
The squad snapped photos of the fogey from many angle so as to reconstruct adetailed 3D modelof the osseous tissue and teeth , and after a thorough examination , they confirmed that the specimen was not only a machaeroidine , but a never - before - seen genus and species of machaeroidine .
Study author Ashley Poust holds the recently namedD. vanvalkenburghaefossil in front of the skull of a saber-toothed cat, a much larger carnivore that emerged millions of years afterD. vanvalkenburghae.
They named the newfound creatureDiegoaelurus vanvalkenburghaein honour of San Diego County , where the specimen was found , and scientist Blaire Van Valkenburgh , a preceding prexy of the Society of Vertebrate Paleontology whose employment greatly influenced scientists ' understanding of carnivore evolution .
" Finding this particular grouping was pretty surprising , " because no other machaeroidine specimens in the U.S. had been incur west of the Rocky Mountains , Poust told Live Science . " We did n’t know that these pass off out here at all . "
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Based on the size of the jawbone , the researchers find out thatD. vanvalkenburghaewas about the size of abobcat , according to the study . The animal carried brand - like , slice up teeth in the back of its mouth and had " sort of trim down tooth in the front — it ’s totally lost the first [ tooth ] behind its down in the mouth canine , " Poust tell . Modern cats also have this opening behind their lower canines , to make blank space for their large upper dogtooth to sting down , he noted . In addition to this gap , D. vanvalkenburghaehad a downturned , bony Kuki that also would have helped to fit its impressive saber tooth .
About 42 million eld ago , D. vanvalkenburghaewould have lived in a very different surroundings than can be found in San Diego County today , Poust noted .
The Eocene kicked off with a period of extensive heating , which fueled the increment of live , humidrainforestsaround the world , according to the American Museum of Natural History . fogy recovered from Santiago Formation advise that the lush rainforests of ancient Southern California were once home to lemur - same high priest , marsupials , boar - sizetapirsand tiny rhino . In possibility , D. vanvalkenburghaemay have preyed on these animals , although the predatory animal ’s exact dieting is nameless , Poust enjoin .
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The new coinage helps fill out the sparse machaeroidine fossil phonograph recording , but it also raises new questions about the computed tomography - like predators , Poust said .
For example , didD. vanvalkenburghaeever coexist and contend for prey with nimravids ? The oldest nimravid remains found in the U.S. are roughly 5 million years younger than the newly identifiedD. vanvalkenburghaefossil , so it would partially depend on when the machaeroidine move nonextant . The exact timing and reason for this extinction also remain mysterious , although it ’s clear that machaeroidines died out many trillion of years before the issue of genuine cavalry sword - toothed cats ( Smilodon ) , Poust noted .
Originally published on Live Science .
