Sinomacrops bondei, a new anurognathid pterosaur from the Jurassic of China and comments on the group

Abstract

Anurognathids are an elusive group of diminutive, potentially arboreal pterosaurs. Even though their monophyly has been well-supported, their intrarelationships have been obscure, and their phylogenetic placement even more. In the present work, we present a new genus and species from the Middle-Late Jurassic Tiaojishan Formation, the third nominal anurognathid species from the Jurassic of China. The new species provides new information concerning morphological diversity for the group. Furthermore, we provide a new phylogenetic analysis incorporating into a single data set characters from diverging phylogenetic proposals. Our results place them as the sister-group of Darwinoptera + Pterodactyloidea, as basal members of the Monofenestrata.

Allometric analysis sheds light on the systematics and ontogeny of anurognathid pterosaurs

“…Considering that the present study focuses only on the phylogeny of Anurognathidae, we excluded non-pterodactyloid species with > 50% missing data and pterodactyloid species with > 25% missing data, leaving 36 species in the matrix. We added five anurognathids, Luopterus mutoudengensis (Lü and Hone, 2012;, Vesperopterylus lamadongensis (Lü et al, 2018;, Sinomacrops bondei (Wei et al, 2021), CAGS-Z070 (Ji and Yuan, 2002) and NJU-57003 (Yang et al, 2019), yielding a total of 41 taxa in the matrix.…”

“…In order to incorporate as many characters as possible that were phylogenetically informative for anurognathid taxa, we evaluated each character in the original diagnosis and additional characters in Hone (2020) and Wei et al (2021) (Supplemental Data 2) prior to inclusion in the character list (Supplemental Content). Characters were omitted if (1) they are uninformative (i.e., same states in all anurognathids), (2) the corresponding skeletal elements are poorly preserved, (3) they already exist in Longrich et al (2018), or (4) they show allometric growth bias.…”

“…0.24 to 1 m in wingspan and of varying ontogenetic status. Nine specimens (including specimens of Anurognathus, Dendrorhynchoides, Luopterus, Sinomacrops and Batrachognathus, and specimens NJU-57003 and CAGS-Z070 (Dalla Vechia, 2002;Yang, et al, 2019;Wei et al, 2021)) show characteristics of immaturity, e.g., unfused articular bones, scapulacoracoid, pelvis and cranial elements. In contrast, the holotypes of Jeholopterus and Vesperopterylus show osteological maturity and are thus (sub)adults (Wang et al, 2002;.…”

“…Inadequate recognition of ontogenetic status in previous studies of anurognathids has raised concerns about confounding ontogenetic variation with systematics . In particular, many length ratios used as diagnostic (e.g., Wang et al, 2002;Lü and Hone, 2012;Wei et al, 2021) or in analyzing characters (e.g., Kellner, 2003;Lü et al, 2018) may change greatly during growth (Delfino and Sánchez-Villagra, 2010). Previous statistical studies on ontogenetic changes in other pterosaurs have suggested or prompted taxonomic revisions for some taxa (e.g., Bennett, 1995Bennett, , 1996Bennett, , 2007bBennett, , 2013Jouve, 2004;Vidovic and Martill, 2014).…”

A taxonomic revision of the Sinopterus complex (Pterosauria, Tapejaridae) from the Early Cretaceous Jehol Biota, with the new genus Huaxiadraco

“…We performed a cladistic analysis using the software TNT 1.5 ( Goloboff, Farris & Nixon, 2008 ), which was divided in two steps, following the same protocol as previously described by Wei et al (2021) . New Technology Search was used for the first search (using Sectorial Search, Ratchet, Drift and Tree fusing, default parameters), with random seed = 0.…”