| Moschowhaitsia | |
|---|---|
 | |
| Life restoration ofMegawhaitsia vjuschkovi | |
Scientific classification | |
| Domain: | Eukaryota |
| Kingdom: | Animalia |
| Phylum: | Chordata |
| Clade: | Synapsida |
| Clade: | Therapsida |
| Clade: | †Therocephalia |
| Family: | †Whaitsiidae |
| Genus: | †Moschowhaitsia Tatarinov,1963 |
| Type species | |
| †Moschowhaitsia vjuschkovi Tatarinov, 1963 | |
| Other species | |
Moschowhaitsia is an extinct genus oftherocephaliantherapsids from theLate Permian (Guadalupian) ofRussia andChina. Thetype species,Moschowhaitsia vjuschkovi, was discovered in theChangxingian-agedArchosaurus Assemblage Zone of Russia and named in 1963 by Russian palaeontologistLeonid Petrovich Tatarinov. A second species was discovered inJingtai County ofGansu,China in 2020 and named asM. lidaqingi in 2023 by Jun Liu and Fernando Abdala, the first whaitsiid therocephalian to be discovered in China. It was among the larger carnivores in the faunal assemblages it occurred in, with a skull-length of up to 25 centimetres (9.8 in) inM. vjuschkovi and an even larger estimated 35 centimetres (14 in) forM. lidaqingi, one of the largest therocephalian skulls reported.[1][2] Thegenus nameMoschowhaitsia alludes to two other therocephalians,Moschorhinus andWhaitsia (ajunior synonym ofTheriognathus), due to the structure of its palate combining physical features of both these genera.[3]
Moschowhaitsia is a member of the derived therocephaliancladeWhaitsiidae, ranked as afamily under traditionalLinnaean taxonomy. Tatarinov initially assignedMoschowhaitsia to its ownmonotypicsubfamily of whaitsiids,Moschowhaitsiinae, on the basis that it appeared to him as an intermediate form bridging the anatomy of two other subfamilies of whaitsiids, Whaitsiinae and Moschorhininae.[3] Some later researchers, including Tatarinov himself, would later elevateMoschowhaitsia to family level distinction (Moschowhaitsiidae), along with other subtaxa of whaitsiids, although nonetheless retaining the existing close taxonomic relationships under the superfamilyWhaitsioidea.[4][5]
However, later research of therocephalian evolution usingcladistics regardless of taxonomic ranking have found that many of the various whaitsiids/whaitsioids are in fact only distantly related to each other, with many belonging to the earlier-diverging cladeAkidnognathidae instead (including members of Moschorhininae). As a clade, Whaitsiidae has been restricted to therocephalians closest toTheriognathus (thesenior synonym ofWhaitsia). As such,Moschowhaitsia is a member of Whaitsiidae as cladistically defined, and is one of the clade's only representatives from Laurasia.[6]
Acladogram depicting the relationships of bothM. vjuschkovi andM. lidaqingi is shown below, reproduced from Liu & Abdala (2023) and simplified to show the relationships of whaitsioid therocephalians:[2]
The strict-consensus tree shown above did not recoverM. vjuschkovi andM. lidaqingi as each other's sister taxa (found as such in only six of the 30 most parsimonious (i.e. shortest) trees). However, Liu and Abadala (2023) nonetheless assignedM. lidaqingi toMoschognathus as both species show more similarities to each other in morphology than either does to other whaitsiids. Such traits include the number of incisors and postcanine teeth, rugose bone on the front edge of the orbit, and a notch in themaxilla in front of the canine.[2]
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