2022/11/01 by Yoshiaki Ishida, Ha Thai Trinh, Ben Thuy +6 · 1 citation
Agricultural and Biological Sciences · Earth and Planetary Sciences · #Echinoderm biology and ecology #Paleontology and Stratigraphy of Fossils #Marine and coastal plant biology
paper · doi:10.2517/pr210014
openalex publication_date 2022/11/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/06/11
The fossil record of brittle stars, one of the five extant classes of echinoderms, is still rather poorly known. In particular for the Triassic Period, occurrences published to date are strongly biased toward Europe, with only two exhaustively described taxa recorded from the East Asian part of the Tethys Ocean. Here, we record new ophiuroids from the Carnian (Upper Triassic) of the Me area in Ninh Binh Province, Vietnam. The fossils comprise articulated disks and arm fragments preserved as external molds, all original calcite dissolved. We introduce a new genus and species, Triadoleucella meensis, for these specimens that represent the oldest known member of the order Ophioleucida. The ophiuroids were found in mudstones deposited in outer shelf environments below storm wave base. The intact articulation, combined with random orientation and intense fragmentation of individuals suggest effective burial by downslope mudflow prior to or soon after death.