New Material of the Pterosaur Gladocephaloideus Lü et al., 2012 from the Early Cretaceous of Liaoning Province, China, with Comments on Its Systematic Position

Abstract

Although there are nine genera of ctenochasmatoids reported from the Jehol Biota, at present each is known from a specimen that has either a skull or a relatively complete postcranial skeleton. A nearly complete juvenile specimen of Gladocephaloideus from the Lower Cretaceous Jiufotang Formation of Sihedang, Lingyuan of Liaoning Province is the most complete ctenochasmatoid preserved to date with a skull and postcranial skeleton. Based on the holotype (IG-CAGS 08–07) and the nearly complete new specimen (JPM 2014–004), the diagnosis of Gladocephaloideus is amended: approximately 50 teeth in total with sharp tips; small nasoantorbital opening, occupying approximately 13% of total skull length; ratio of prenarial rostrum length to skull length approximately 0.63; deep groove along the mid-line of the mandibular symphysis; length to width ratio of the longest cervical vertebra = 4.1; ratio of femur length to tibia length = 0.61; tibia as long as the wing-phalange 1. Phylogenetic analysis recovers Gladocephaloideus within the clade Ctenochasmatidae. Gladocephaloideus has a closer relationship to the Chinese Pterofiltrus rather than to other ctenochasmatid pterosaurs. Microstructure of limb bones implies that JPM 2014–004 represents an early juvenile of Gladocephaloideus jingangshanensis, and that the type specimen is not a fully grown specimen either. We assume that the holotype may equate to the late juvenile or sub-adult developmental stage of Gladocephaloideus.

Dietary diversity and evolution of the earliest flying vertebrates revealed by dental microwear texture analysis

“…Second, by mapping pterosaur PC scores from the first two reptile texture-dietary axes onto each tree. The results using the Lü et al 33 phylogeny (Fig. 4, Supplementary Figs.…”

“…total vertebrates in diet Increasing proportion of total invertebrates in dietIncreasing proportion of 'softer' invertebrates in diet omnivores Pterosaur dietary evolution. a Phylo-texture-dietary space of pterosaur microwear from projecting a time-calibrated, pruned tree from Lü et al33 onto the first two PC axes of the extant reptile texture-dietary space. b Ancestral character-state reconstruction of pterosaur dietary evolution from mapping pterosaur PC 1 values onto a time-calibrated, pruned tree from Lü et al33 .…”

The first pterosaur basihyal, shedding light on the evolution and function of pterosaur hyoid apparatuses

“…The depth of the posterior end of the new material was four times large as that of the holotype of Gladocephaloideus, which indicates that the sizes are quite different between these two specimens. The holotype was considered to be an adult individual (Lü et al, 2012), but was later reconsidered to be a late juvenile or sub-adult individual (Lü, Kundrát & Shen, 2016). It is reasonable to believe that the new material is from an adult G. jingangshanensis and is quite larger than the holotype.…”

A new wing skeleton of <i>Forfexopterus</i> (Pterosauria: Ctenochasmatidae) from the Early Cretaceous Jehol Biota reveals a developmental variation

“…126-122 Ma;Chang et al, 2009Chang et al, , 2017, such as Eosipterus, Feilongus, Beipiaopterus, Elanodactylus, Gegepterus, Pterofiltrus, Cathayopterus, and Gladocephaloideus. Recently, Feilongus and Gladocephaloideus were also reported from the overlying Jiufotang Formation (e.g., Wang et al, 2005;Lü et al, 2016). In addition, two taxa -Moganopterus and Forfexopterus -are only known from the Jiufotang Formation in Lamadong Town, Jianchang County, western Liaoning Province Jiang et al, 2016).…”

“…In addition, two taxa -Moganopterus and Forfexopterus -are only known from the Jiufotang Formation in Lamadong Town, Jianchang County, western Liaoning Province Jiang et al, 2016). In this area, the lacustrine sediments are recognized as the Jiufotang Formation based on biostratigraphic data (e.g., Pan et al, 2015;Wu et al, 2018) and isotopic dating (120 ± 1.0 Ma; Jiang et al, 2016).…”