A new paratypothoracin aetosaur (Archosauria: Pseudosuchia) from the Upper Triassic Dharmaram Formation of India and its biostratigraphic implications

Article Type

Research Article

Publication Title

Journal of Vertebrate Paleontology

Abstract

The Upper Triassic lower Dharmaram Formation of India has yielded a highly diverse archosaur-dominated fauna that included a paratypothoracin aetosaur Venkatasuchus armatum, a plateosaurian sauropodomorph Jaklapallisaurus asymmetrica, a neotheropod, and a Mystriosuchinae phytosaur. In this current contribution, we describe a new paratypothoracin aetosaur taxon, Kuttysuchus minori gen. et sp. nov., from the same horizon based on several isolated paramedian osteoderms recovered from a single fossil locality. These osteoderms are characterized by a weakly raised anterior bar with a short pointed anteromedial edge, deeply incised dorsal surface ornamentation composed of strongly radial pattern of ridges and grooves with a low density of pits surrounding a pointed pyramidal dorsal eminence placed near the posterior margin and a weakly developed ventral strut or transverse thickening. These features show similarity of the specimens to that of both Paratypothorax and Stagonolepis olenkae and strongly differentiate Kuttysuchus from the other paratypothoracin Venkatasuchus known from the same stratigraphic unit. Our phylogenetic analysis recovered Kuttysuchus as an early-diverging taxon within the clade Paratypothoracini. The rich record of paratypothoracin aetosaurs, along with that of a mystriosuchine phytosaur positively suggests a mid-to-late Norian age, though the age could be extended to the Rhaetian as suggested by previous studies. The current study considerably enhances knowledge of aetosaur diversity during the Late Triassic, particularly on Gondwana, and raises the potential of recovering a rich Gondwanan record of Paratypothoracini in future.

DOI

10.1080/02724634.2024.2439533

Publication Date

1-1-2024

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