First-known ginglymodian fish found from the middle triassic of Eastern Yunnan Province, China

Jan 09, 2012
Fig. 1: Holotype of Kyphosichthys grandei gen. et sp. nov. (IVPP V10108) Credit: XU Guanghui

The Ginglymodi are a group of ray-finned fishes that make up one of three major subdivisions of the infraclass Neopterygii. Extant ginglymodians are represented by gars, which inhabit freshwater environments of North and Central America and Cuba. Drs. XU Guanghui and WU Feixiang, Institute of Vertebrate Paleontology and Paleoanthropology (IVPP), Chinese Academy of Sciences, reported the discovery of well-preserved fossils of a new ginglymodian, Kyphosichthys grandei gen. et sp. nov., from the Middle Triassic (Anisian) marine deposits (Guanling Formation) in Luoping, eastern Yunnan Province, China. The discovery documents the first known fossil record of highly deep-bodied ginglymodians, adding new information on the early morphological diversity of this group.

The new ginglymodian species is deep-bodied with a strongly arched hump between head and dorsal fin, and was found in deposits composed by thin lime mudstone interlaid with dark shale, siliceous concretion, and zebra limestone of apparent marine origin. The lithofacies of this fossil site indicate a platform margin or platform margin slope environment. Along with this new fish is a taxonomically rich fossil assemblage, including plants, invertebrates, , and other kinds of fishes.

The studies of functional morphology of extant deep-bodied fishes indicate that Kyphosichthys is not a fast swimmer but has a good performance in precise maneuvering, representing a morphological adaptation to structurally complex habitats (e.g. thick macrophyte beds, rocky areas, or ), which differs from the other members of this group. “The discovery of the new deep-bodied ginglymodian indicates that the earliest ecological diversification of the Ginglymodi occurred at least in the Middle Triassic”, said XU Guanghui, associate professor of the IVPP and first author of the study, “Its occurrence adds significantly to the ecological diversity of the already known vertebrate fauna from the Middle Triassic marine ecosystem of the eastern Yangtze Sea, which once sustained taxonomically and functionally diverse marine reptiles and other fishes.”

The earliest known neopterygians are found in the Early Triassic. Greater diversification of the Neopterygii occurred in the Middle Triassic, and the Triassic is a period of particular interest to the study of the neopterygian evolution. A cladistic analysis was carried out to assess the phylogenetic relationships of the new fish taxon Kyphosichthys with other taxa of the Neopterygii. The analysis result supports the hypothesis that the Ginglymodi are more closely related to the Halecomorphi than to the Teleostei. These phylogenetic relationships agree with Grande in the resurrection of the term Holostei to include the Ginglymodi and Halecomorphi within the crown-group Neopterygii. Kyphosichthys was identified as a ginglymodian in the Holostei. The analysis also shows that a highly deep and short fish body type has independently evolved at least three times in the stem-group neopterygians, ginglymodians, and basal teleosts within the lower neopterygians of the Triassic, represented respectively by Felberia, Kyphosichthys, and Dapedium.

The original paper was published in the journal of Chinese Science Bulletin (No.1: 111-118) in January 2012.

Explore further: Scientists seek more tombs at ancient Greek site

add to favorites email to friend print save as pdf

Related Stories

New Eosauropterygian found in Eastern Yunnan, China

Jun 01, 2011

The marine Triassic deposits in southwestern China have yielded numerous vertebrate fossils (ichthyosaurians, sauropterygians, thalattosaurians, and fishes). A new eosauropterygian, Diandongosaurus acutidentatus ...

New Triassic Diapsid reptile found in Southwestern China

Nov 21, 2011

Paleontologist LI Chun, Institute of Vertebrate Paleontology and Paleoanthropology (IVPP), Chinese Academy of Sciences, and his research team, reported a new genus and species of marine reptile, Sinosaurosphargis ...

Chinese report important fish fossil find

May 05, 2006

Chinese researchers say a newly discovered fish species that lived more than 400 million years ago may represent a bridge between two vertebrate lineages.

New leuciscin fish found in northern China

Jun 02, 2011

SU De-Zao, a retired paleoichthyologist of Institute of Vertebrate Paleontology and Paleoanthropology, Chinese Academy of Sciences, found a new paleogene leuciscin fish, Tianshanicus liui sp. nov., in the ...

Recommended for you

Laser from plane discovers Roman goldmines in Spain

Nov 20, 2014

Las Médulas in León is considered to be the largest opencast goldmine of the Roman Empire, but the search for this metal extended many kilometres further south-east to the Erica river valley. Thanks to ...

Ancient New Zealand 'Dawn Whale' identified

Nov 18, 2014

University of Otago palaeontologists are rewriting the history of New Zealand's ancient whales by describing a previously unknown genus of fossil baleen whales and two species within it.

User comments : 0

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.