A new perleidid neopterygian fish from the Early Triassic (Dienerian, Induan) of South China, with a reassessment of the relationships of Perleidiformes

Abstract

Neopterygii is the largest clade of ray-finned fishes, including Teleostei, Holostei, and their closely related fossil taxa. This clade was first documented in the Early Carboniferous and underwent rapid evolutionary radiation during the Early to Middle Triassic. This article describes a new perleidid neopterygian species, Teffichthys elegans sp. nov., based on 13 well-preserved specimens from the lower Daye Formation (Dienerian, Induan) in Guizhou, China. The new species documents one of the oldest perleidids, providing insights into the early diversification of this family. The results of a phylogenetic analysis recover Teffichthys elegans sp. nov. as the sister taxon to Teffichthys madagascariensis within the Perleididae. T. elegans sp. nov. shares three derived features of Perleididae: the length of the anteroventral margin of the dermohyal nearly half the length of the anterodorsal margin of the preopercle; the anteroventral margin of the preopercle nearly equal to the anterior margin of the subopercle in length; and the anteroventral margin of the preopercle one to two times as long as the anterodorsal margin of the preopercle. It possesses diagnostic features of Teffichthys but differs from T. madagascariensis by the following features: presence of three supraorbitals; six pairs of branchiostegal rays; relatively deep anterodorsal process of subopercle; absence of spine on the posterior margin of the jugal; and pterygial formula of D26/P14, A22, C36/T39-41. The Perleidiformes are restricted to include only the Perleididae, and other previously alleged ‘perleidiform’ families (e.g., Hydropessidae and Gabanellidae) are excluded to maintain the monophyly of the order. Similar to many other perleidids, T. elegans sp. nov. was likely a durophagous predator with dentition combining grasping and crushing morphologies. The new finding also may indicate a relatively complex trophic structure of the Early Triassic marine ecosystem in South China.

Large durophagous fish from the Spathian (late Early Triassic) of Romania hints at earlier onset of the Triassic actinopterygian revolution

“…Xu 2020; Yuan et al . 2022). In † Polzbergia , the paired premaxilla is relatively deep and bears a small number of elongated prehensile teeth.…”

“…However, the pattern of the post-PTMBE diversification dynamics and the timing of appearance of various lifestyle adaptations, termed the 'Triassic actinopterygian revolution' (Romano et al 2016;L opez-Arbarello & Sferco 2018), are obscured by: (1) a hiatus in the fossil record of bony fish from the late Early Triassic (Spathian, late Olenekian) to the early middle Anisian (Bithynian; Middle Triassic), dubbed the Spathian-Bithynian Gap (SBG; Romano 2021); and (2) uncertainties about phylogenetic interrelationships among stem neopterygians and stem actinopterygians (e.g. Hurley et al 2007;Giles et al 2017;Xu 2020;Argyriou et al 2022;Yuan et al 2022). These uncertainties are partially caused by the limited informativeness of the two-dimensional (crushed) mode of preservation of most fossils from that interval, which allows for the study only of their exoskeletons and not of internal features.…”

“…2022; Yuan et al . 2022). These uncertainties are partially caused by the limited informativeness of the two‐dimensional (crushed) mode of preservation of most fossils from that interval, which allows for the study only of their exoskeletons and not of internal features.…”

A Mesozoic fossil lagerstätte from 250.8 million years ago shows a modern-type marine ecosystem

“…Two different coelacanth species have been found so far and are the largest macrofossils in the Guiyang Biota. All of these specimens show an estimated body length of >0.5 m, with the largest specimen reaching a body length of ~1 m. More than 10 species of at least six actinopterygian orders have been identified, including stem actinopterygians (Palaeonisciformes and Ptycholepiformes), chondrosteans (Acipenseriformes), stem neopterygians [Perleidiformes ( 27 ) and Polzbergiiformes], and holosteans (Parasemionotiformes). Additionally, Chondrichthyes, represented by hybodontiform teeth, have also been found (Fig.…”

Macro- And Micromorphology of Scales from an Endemic South American Actinopterygian Family (Pseudobeaconiidae, Triassic, Cuyana Basin)

“…THE TRIASSIC is a crucial period to understand the evolutionary history of most main living clades of Actinopterygii (Arratia, 2004;Arratia & Tintori, 2004;Smithwick & Stubbs, 2018;Benton & Wu, 2022). Besides, Triassic actinopterygian clades worldwide are currently under discussion from different records from Europe and Asia (e.g., Sun et al, 2013;Tintori et al, 2014;Xu et al, 2015;Arratia, 2017;Shen & Arratia, 2022;Yuan et al, 2022). The records of Triassic actinopterygian from Argentina are very rich (López-Arbarello et al, 2006;López-Arbarello & Zavattieri, 2008;López-Arbarello et al, 2010;Gouiric-Cavalli et al, 2017a, 2017b and, the study of this fauna contribute to the understanding of morphological, evolutionary and biogeographic patterns in the present global context.…”