Palaeontologists from the University of New South Wales have unearthed the fossils of three new species belonging to the thylacine genus. Basitinus, Nimbakinusand Ngamalasinas It inhabits upper Oligocene sediments in the Riversleigh World Heritage Area, northwest Queensland, Australia. Bassinus timforkneri, Nimbasinus peterbridgeand Ngamalasinas NigermalbeniThese new species are among the oldest known thylacines and indicate an earlier diversification of the family Thylacidae. Thylacine More than previously understood.
The three new species of Pectiniidae lived during the Late Oligocene epoch, between 25 and 23 million years ago.
The largest of these is Bassinus timforkneriThey weigh between 7 and 11 kg, roughly the same size as a large Tasmanian devil.
“Like the Tasmanian devil, Basisinas timforkneri “They could easily crush the bones and teeth of their prey,” said lead author Tim Churchill, a doctoral student at the University of New South Wales.
“But up until now, we've only seen much smaller Bassinus TurnbulliiWeighing in at around 2.7 kg, this dinosaur is the only thylacine relative found in the Late Oligocene.
“The lower jaw and teeth, including an isolated first molar, were found at the Hiatus site at Riversleigh, which is even older than the White Hunter site where B. turnbrii was previously found.”
“This will Basisinas timforkneri It is undoubtedly the oldest thylacine ever discovered.”
The second species is Nimbasinus peterbridgeIt was slightly larger than a long-eared quoll and weighed about 3.7kg.
The species was described from a nearly complete jawbone from the White Hunter site at Riversleigh.
“Nimbasinus peterbridge “It was probably a more generalist predator, targeting small mammals and other prey in the ancient woodland of Riversleigh,” Professor Mike Archer, from the University of New South Wales, said.
“We think it may have been directly related to only one other species. Nimbakinus,big Nimbasinus dicksoni (5-7kg) was discovered in 15 million year old deposits at Riversleigh.”
“This group of thylacines, Thylacine.”
“The other two new species described here appear to represent distinctive side branches on the increasingly complex thylacine phylogenetic tree.”
“This means Nimbasinus peterbridge It is probably the oldest known direct ancestor of the Tasmanian tiger.”
The third new species, Ngamalasinas NigermalbeniIt weighed about 5.1kg and was about the size of a red fox. This one was also unearthed at the White Hunter site in Riversleigh.
“This was a highly carnivorous thylacine,” said Dr Sue Hand, from the University of New South Wales.
“We know this because the cutting edges of the lower molars are elongated and have deep, V-shaped meat-cutting notches.”
“Ngamalasinas Nigermalbeni These notches were more developed than in any other thylacine species of similar size.”
The existence of three distinct lineages of specialized thylacines in the Late Oligocene highlights how rapidly this group of marsupials has diversified since they first appeared in the fossil record, the researchers say.
“These new species have very different dental adaptations, suggesting that several unique carnivore forest niches existed during this time,” Churchill said.
“All of these lineages became extinct by 8 million years ago, except for the lineage that gave rise to modern thylacines.”
“The previous idea that Australia was dominated by reptilian carnivores for the last 25 million years is steadily being disproved as each new discovery adds to the fossil record of these new thylacine-like marsupial carnivores,” Prof Archer said.
“The diversity of mammalian carnivores in Rivers Leaf during this period rivals any other ecosystem, including the large dispersal of mammalian carnivores that developed in South America,” Churchill added.
of study this month, Journal of Vertebrate Paleontology.
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Timothy J. Churchill othersThree new opossum species (Marsupialia, Opossumidae) discovered from Late Oligocene deposits in the Riversleigh World Heritage Area, north-west Queensland. Journal of Vertebrate PaleontologyPublished online September 6, 2024; doi: 10.1080/02724634.2024.2384595
Source: www.sci.news
