Subjects: Biology >> Zoology submitted time 2024-01-28 Cooperative journals: 《古脊椎动物学报》
Abstract： As a small to middle-sized bovid, Hispanodorcas had previously only been found in the pan-Mediterranean region and South Asia. Its taxonomic classification at the tribe level has been a subject of debate, with possible associations to Antilopini, Reduncini, or Oiocerini. Here, we report on the first discovery of Hispanodorcas in East Asia, H. longdongica sp. nov. from the Daidian Locality in China, dating to the early Baodean age (~8–7 Ma). The new material consists of five skulls with varying states of preservation and provides the most complete osteological information on Hispanodorcas to date. It features a long, slender, and posteriorly curved horncore with a weak homonymous twist and both laterodorsal and medioventral grooves, which is characteristic of Hispanodorcas. This new species is characterized by having the smallest size amongst all known Hispanodorcas species, a weakly curved brain case in the facial region, and poorly developed posterior and anterior basilar tuberosities. These primitive characteristics suggest that H. longdongica may represent an early evolutionary stage of this genus. Furthermore, they indicate that Hispanodorcas might have directly evolved from the Gazella stock. The homonymous twist in the horncore, which aligns with Oiocerini, may be a case of homoplasy.
Subjects: Biology >> Zoology submitted time 2023-07-12 Cooperative journals: 《古脊椎动物学报》
Abstract： The previously alleged ‘eugnathid amiiform’ Sinoeugnathus kueichowensis is a small-sized halecomorph from the Middle Triassic (Ladinian) marine deposits of Guizhou and Yunnan, China. A morphological redescription and taxonomic revision of this taxon are provided based on a detailed examination of 15 new specimens. Among them, IVPP V24315 (standard length = 64 mm) is appointed as the neotype, given that the holotype is missing. Studies of these specimens revealed some morphological details previously undescribed or misidentified for this taxon, including a hatchet-shaped antorbital, two broad suborbitals, a sensory canal in the maxilla, and three pairs of extrascapulars. For the first time, Sinoeugnathus was incorporated into an analysis of halecomorph phylogeny, and the results recover it as the sister taxon of the Anisian Subortichthys from Luoping, Yunnan, and both are grouped with two Ladinian genera Allolepidotus and Eoeugnathus from the Monte San Giorgio area into a monophyletic group (namely Subortichthyidae fam. nov. herein) at the base of Ionoscopiformes. This taxonomic reassessment of Subortichthys provides new insights into the phylogeny and paleogeographic evolution of Ionoscopiformes.
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