Revision of Saurorhynchus (Actinopterygii: Saurichthyidae) from the Early Jurassic of England and Germany

Abstract

Abstract. Saurichthyidae is a speciose group of fishes, ranging from the Late Permian to the Middle Jurassic. Early Jurassic saurichthyids are usually considered morphologically less disparate and taxonomically less diverse than their Triassic counterparts, consisting of only two valid species. These were historically differentiated almost entirely based on cranial ratios, and both had stratigraphic ranges spanning the Early Jurassic. Here, we revise the Early Jurassic saurichthyid fishes of Europe based on restudy of the type material of Saurorhynchus brevirostris (Woodward, 1895) and S. acutus (Agassiz, 1844). We identify four species based on cranial osteology: S. acutus, S. brevirostris, S. anningae sp. nov., and S. hauffi sp. nov. Saurorhynchus brevirostris and S. anningae sp. nov. are known from the Sinemurian of England only, whereas S. acutus and S. hauffi sp. nov. share a broad European distribution during the Toarcian, from southwestern Germany to England. Saurorhynchus anningae sp. nov. and S. brevirostris, in particular, show disparity in such ecomorphologically important traits as cranial fineness, and tooth and jaw morphology. In contrast, S. acutus and S. hauffi sp. nov. show much lower levels of disparity, differing from each other in nostril morphology, dermal ornamentation, and position of the lateral extrascapular. The new species do not increase diversity estimates for Saurorhynchus in either the Sinemurian or Toarcian interval.

Regional disparity in the axial skeleton of Saurichthyidae and implications for axial regionalization in non‐teleostean actinopterygians

“…Saurorhynchus species group (sensu Maxwell et al, 2015) Detailed data for this clade is only available for Saurorhynchus hauffi (Early Jurassic; Maxwell & Stumpf, 2017). Region I consists of~4 neural arch-like elements, and is differentiated from Region II by the block-like shape of the centra and the relative reduction of the prezygapophyses and neural spines (Fig.…”

A new Pliensbachian elasmobranch (Vertebrata, Chondrichthyes) assemblage from Europe, and its contribution to the understanding of late Early Jurassic elasmobranch diversity and distributional patterns

“…The clayey lower Toarcian interval (elegantulum to exaratum subzone) of Grimmen is renowned for having produced a diverse fauna of vertebrates, including fish, secondarily marine reptiles, and dinosaurs (e.g., Haubold 1990;Thies 1989;Maisch and Ansorge 2004;Konwert and Stumpf 2017;Stumpf 2016;Stumpf et al 2015Stumpf et al , 2017Maxwell and Stumpf 2017;Konwert and Hörnig 2018). Likewise, vertebrate material also has been reported from the upper Pliensbachian of Grimmen (e.g., Ernst 1967Ernst , 1991Kutscher 1988;Buchholz 2012;Stumpf et al 2017), but little detailed taxonomic research has been conducted, and a comprehensive study of the vertebrate fauna thus has not been provided so far.…”

Early Jurassic diversification of pycnodontiform fishes (Actinopterygii, Neopterygii) after the end-Triassic extinction event: evidence from a new genus and species,Grimmenodon aureum

“…observ.). The fauna mainly comprises actinopterygians (e.g., Jaekel, 1929 ; Malzahn, 1963 ; Thies, 1989 ; Ansorge, 2007 ; Ansorge and Obst, 2015 ; Konwert and Stumpf, 2017 ; Maxwell and Stumpf, 2017 ), followed by marine reptiles (Maisch and Ansorge, 2004 ; Stumpf, 2016 ) and rare chondrichthyans (Ansorge, 2007 ). These faunal elements occur alongside an extraordinarily rich terrestrial entomofauna (Ansorge, 1996 , 2003 ), indicating the presence of suitable environments nearby.…”