The Permotriassic branchiosaurid Tungussogyrinus Efremov, 1939 (Temnospondyli, Dissorophoidea) from Siberia restudied

摘要

The enigmatic temnospondyl amphibian Tungussogyrinus bergi Efremov, 1939 shares clear synapomorphies with other branchiosaurids indicated by an anteriorly elongated in_fratemporal fossa and small branchial denticles. Therefore Tungussogyrinus clearly be_longs to the dissorophoid family Branchiosauridae. This species is characterized by a number of derived features among temnospondyls: (1) an unusually elongated anterodor_sal process of the ilium; (2) the character complex concerning the tricuspid dentition. Tungussogyrinus differs from all other branchiosaurids in these two autapomorphic char_acters. Herein, Tungussogyrinus is thought to represent the closest relative of a clade in_cluding all other branchiosaurids with its placement outside of this clade associated with a new feeding strategy to scrape algae with the tricuspid anterior dentition and the gracile built snout region. The subfamily Tungussogyrininae Kuhn, 1962 is newly defined here by the two derived characters of Tungussogyrinus bergi. All other branchiosaurid genera and species are included in a second subfamily Branchiosaurinae Fritsch, 1879.