Jucha, 2021

Fischer, Valentin, Zverkov, Nikolay G., Arkhangelsky, Maxim S., Stenshin, Ilya M., Blagovetshensky, Ivan V. & Uspensky, Gleb N., 2021, A new elasmosaurid plesiosaurian from the Early Cretaceous of Russia marks an early attempt at neck elongation, Zoological Journal of the Linnean Society 192, pp. 1167-1194 : 1171-1173

JUCHA SQUALEA GEN. NOV., SP. NOV.

Z o o b a n k r e g i s t r a t i o n: P u b l i c a t i o n L S I D: urn:lsid:zoobank.org:pub:8CF4F7E1-7DE3-46DE-ABC3-34C4597DABCC

Genus LSID: urn:lsid:zoobank.org:act:A5A9FD2C-86CB-4CA5-A41A-22812277A226

Species LSID: urn:lsid:zoobank.org:act:8A9BDEF1-47B6-4616-8A70-59B505DBD8FA

Etymology

The generic name comes from the Cyrillic Юха, a snake-like demon associated with water in local Volga– Ural region folklore. In English phonology, the generic name is pronounced ‘you kha’. The specific name is the Latin for coated, covered, rugose, referring to the pyrite layer found on many bones of the holotype.

Holotype

UPM 2756 /1-53, a disarticulated partial skeleton discovered in 2007 by a field crew led by one of us (G.N.U.), comprising 22 cervical centra, 19 dorsal centra including two pectorals, one sacral and four caudals, two partial coracoids, two partial humeri, one radius, one radiale, several metacarpals and phalanges, two complete femora, one tibia, one fibula, fragmentary ribs and gastralia. This specimen originates from the Speetoniceras versicolor Zone ( upper Hauterivian , Lower Cretaceous) in the vicinity of the Slantsevy Rudnik village ( Fig. 1), Ulyanovsk Oblast, European Russia.

Diagnosis

Jucha squalea is characterized by the following autapomorphies among Elasmosauridae : (1) strongly waisted anterior to middle dorsal centra, giving the centrum an hourglass shape in ventral view; (2) massive distally-thickening transverse processes in middle to posterior dorsal vertebrae; (3) absence of a heart-shaped intercoracoid fenestra; and (4) large radius that is anteroposteriorly longer than the humeral head/capitulum.

Jucha squalea is also characterized by a unique combination of features, the most salient of which are as follows: (1) elongated anterior cervicals, with a length-to-height ratio ≤ 1.36, similar to Er. australis

*(and, when needed, ‡):Articulated series. Missing data is indicated by “NA”.

and Kawanectes lafquenianum (Gasparini & Goñi 1985) ( O’Gorman, 2016) ; (2) absence of ventral notch in all cervical centra, as in La. richterae (Sachs et al., 2017) , Callawayasaurus colombiensis ( Welles, 1962) , Zarafasaura oceanis Vincent et al., 2011 ( Lomax & Wahl, 2013; O’Gorman, 2020) and unlike Er. australis (V. Fischer, pers. obs.) and derived elasmosaurids ( Welles, 1943, 1952; Otero, 2016; O’Gorman, 2020); (3) triangular, anteroposteriorly short anteromedial process of the coracoid, as in Styxosaurus ( Welles & Bump, 1949; Welles, 1952; Otero, 2016), Thalassomedon haningtoni Welles, 1943 and Nakonanectes bradti Serratos et al., 2017 ; (4) small, slit-like epipodal notch (also called radioulnar/tibiofibular foramen, spatium interosseum) in both the forelimb and the hindlimb, as in Hydrotherosaurus alexandrae Welles, 1943 , and Morenosaurus stocki Welles, 1943 ; and (5) large tibia that is anteroposteriorly longer than femoral head/capitulum, as in Callawayasaurus colombiensis ( Welles, 1962) .