Cranial remains ofQuetzalcoatlus(Pterosauria, Azhdarchidae) from Late Cretaceous sediments of Big Bend National Park, Texas

Mandibular Bowing and Mineralization in Brown Pelicans

“…While the behaviours of these modern storks do not directly inform us about that of azhdarchids, they indicate that azhdarchid-like rostra are dangerous weapons in some instances. We speculate that both the unusually broad jugal common to azhdarchids (e.g., Cai and Wei 1994;Kellner and Langston 1996) and robust skull construction of some species (Buffetaut et al 2002) are possible indications that azhdarchid skulls were atypically strong compared to those of other pterosaurs, perhaps permitting aggressive use of the rostrum, if required.…”

“…The ecology, lifestyle, and behaviour of this group has been controversial and numerous palaeobehavioural hypotheses have been proposed since the distinctive nature of azhdarchid anatomy became apparent in the 1970s. Suggested lifestyles include obligate scavenging, sediment probing, pursuit swimming, aerial hawking, and dip-or skim-feeding (e.g., Lawson 1975;Nessov 1984;Kellner and Langston 1996;Lehman and Langston 1996; see Witton and Naish 2008 for a recent review). In 2008, we argued that none of these hypotheses were consistent with azhdarchid anatomy or functional morphology, largely because the elongate and relatively inflexible mid-section of the azhdarchid neck precluded feeding in the manners proposed by previous authors (Witton and Naish 2008).…”

“…As indicated by Averianov (2013), these are well known in at least four azhdarchid taxa: Quetzalcoatlus sp., Hatzegopteryx thambema, Bakonydraco galaczi, and Azhdarcho lancicollis (Kellner and Langston 1996;Buffetaut et al 2002;Ősi et al 2005;Averianov 2010). The effect of these structures in pterosaurs has been likened to the mandibular bowing of pelicans, which are famously capable of considerable lateral bowing to facilitate expansion of the enormous gular pouches that they use in capturing fish and other prey (Schreiber and Woolfenden 1975;Fig.…”

“…Many or all azhdarchids possess very long mandibular symphyses which may account for as much as 60% of mandible length (Kellner and Langston 1996;Ősi et al 2005). Thus, for even the anterior tip of the proposed throat sac to reach the water surface, most of the lower jaw has to be submerged.…”

“…We measured the mandible and throat area of Quetzalcoatlus sp. specimen TMM 42161-2 as 440 mm 2 using the freeware program ImageJ v1.37 and images provided by Kellner and Langston (1996) (see Fig. 3 and Table 1).…”