Exceptional fossils from China highlight the origin and early diversification of ionoscopiform halecomorphs

Abstract

Ionoscopiformes, sister to Amiiformes, are an extinct group of marine halecomorphs. In the past decades, ionoscopiforms were known from the Late Jurassic of Europe and the Early Cretaceous of the New World. Here, we introduce the fourth ionoscopiform known from China, Subortichthys triassicus Ma and Xu, 2017 from the early Middle Triassic (Pelsonian, Anisian) of Luoping, Yunnan Province. This paper summarizes information on the osteology of Robustichthys, Subortichthys and Panxianichthys based on well-preserved specimens. The new material reveals that the earliest diversification of ionoscopiforms was well underway in South China by the early Middle Triassic (Anisian).

Keywords

• triassic
• ionoscopiformes
• osteology
• phylogeny
• south china