New remarkable Late Jurassic teleosts from southern Germany: Ascalaboidae n. fam., its content, morphology, and phylogenetic relationships

作者：Arratia G^*

来源：Fossil Record, 2016, 19(1): 31-59.

DOI：10.5194/fr-19-31-2016

Complete morphological descriptions, as preservation permits, are provided for a new Late Jurassic fish taxon (Ebertichthys ettlingensis n. gen. et n. sp.) and a revision of some morphological features of Ascalabos voithii Graf zu Munster from the Solnhofen limestones, southern Germany. A new family, Ascalaboidae, is erected to include the two species. The new family is supported by numerous synapomorphies, e.g., maxilla with external row of small conical teeth increasing in size posteriorly, absence of gular plate, low number of vertebrae (34 to 39), deep and narrow supracleithrum - deeper than opercle, and vertebral centrum formation of caudal region including paired chordacentra (pseudo-diplospondyly) that fuse in early ontogeny forming one chordacentrum that is later surrounded by an autocentrum. A phylogenetic analysis based on 173 characters and 42 taxa was performed. Following the phylogenetic hypothesis, the sister-group relationship [AscalabosaEuro-+aEuro-Ebertichthys]aEuro-+aEuro-more advanced teleosts stands above the node of Leptolepis coryphaenoides plus more advanced teleosts and below the node of Tharsis plus more advanced teleosts, and the new taxa are interpreted as extinct and primitive forms within Teleostei. The new genus and species is endemic and restricted to one Upper Jurassic locality - Ettling - whereas Ascalabos is known from different localities in the Solnhofen limestones, with the exception of Ettling.

• 出版日期2016