Tapejara wellnhoferi
- 演化之聲
- 4d
- 4 min read
Updated: 1d
Age
Cretaceous（Aptian-Albian）
112 Ma
Taxonomy
Kingdom: Animalia
Phylum: Chordata
Class: Sauropsida
Order: Pterosauria
Family: Tapejaridae
Genus: Tapejara
Species: Tapejara wellnhoferi
Morphological description
Tapejara wellnhoferi was a pterosaur from the Early Cretaceous of Brazil, distinguished by an extremely exaggerated cranial crest in proportion to the rest of the skull. The skull itself was relatively short and high, with the rostral tip deflected ventrally into a pointed beak and entirely lacking teeth. A large opening on the side of the skull, the nasoantorbital fenestra, gave the skull an exceptionally lightweight appearance. The upper jaw was formed by the strong fusion of the premaxilla and maxilla, and supported a tall median sagittal crest rising dorsally from the snout. Behind this, a posteriorly extended frontoparietal crest projected from the rear part of the skull.
On the lower jaw, a median mandibular crest was present along the ventral side, although this crest appears to have been less pronounced in smaller individuals. The occlusal margin of the mandible was inclined anteroventrally, and its dorsal surface formed a concave depression.
The cervical vertebrae were short and relatively low, and bore large pneumatic foramina. The humerus was pierced by both dorsal and ventral pneumatic openings, a particularly characteristic feature within this group. The scapula was long and blade-like. As in other pterosaurs, the wing membrane was supported primarily by the extremely elongated fourth finger, while the hindlimbs were also well developed.
Etymology
Genus name Tapejara: derived from the Tupi language of Indigenous peoples of Brazil, and is generally interpreted as meaning "ancient being," "old one," or "ancient creature."
Species name wellnhoferi: named in honour of the German pterosaur researcher Peter Wellnhofer, in recognition of his major contributions to pterosaur studies.
Biological description
Tapejara wellnhoferi lived in the sedimentary environments of the Araripe Basin in Early Cretaceous Brazil. Known specimens come from the Romualdo Member of the Santana Formation, a region that at the time formed part of a tropical lagoon–archipelago system influenced by both marine and terrestrial inputs. This indicates that Tapejara wellnhoferi inhabited a landscape of coastlines, lagoons, shallow waters, islands, and rocky escarpments.
From the perspective of flight dynamics, Tapejara wellnhoferi was likely a highly agile flying animal with excellent aerial control. At first glance, its enormous cranial crest seems like a structure that would only increase drag and destabilize the body in flight. However, it may actually have had an aerodynamic role. If the posterior edge of the crest was connected to a vertically aligned sail-like soft tissue structure, the entire crest complex may have functioned somewhat like a rudder, helping the animal make rapid directional adjustments while airborne.
Anatomical analyses further suggest that Tapejara wellnhoferi possessed a well-developed flight musculature capable of sustaining powered flapping flight rather than relying only on gliding. It was probably able to take off from perches, the ground, or even the water surface, and could also land on the ground with relative stability. Computer simulations indicate a glide angle close to 4° and a cruising speed of about 27 km/h. These results suggest that it was well suited for exploiting updrafts along coastlines or island margins, and may also have circled over tropical waters.
Its neuro-sensory system also appears to have been highly developed. Studies of the endocranial cavity and endocast indicate that the brain of Tapejara wellnhoferi shared several notable features with those of birds and other advanced pterosaurs. In particular, the ocular lobes and flocculi were relatively well developed, structures associated with visual processing, stabilization of the head and eyes, and flight posture control. For an animal that had to make rapid aerial adjustments while carrying such a large cranial crest, efficient sensory integration and balance control would have been essential for survival.
Some known specimens of Tapejara wellnhoferi have been interpreted as immature individuals, including examples with less developed mandibular crests and smaller skeletal dimensions. Researchers have therefore suggested that the degree of development of the cranial and mandibular crests may have been related to ontogeny, and may also have involved sexual dimorphism. This makes it increasingly plausible that the huge crest served, at least in part, as a structure involved in social signalling, sexual selection, or individual recognition.
As for diet, the absence of teeth and the downturned shape of the beak and occlusal profile have long led researchers to infer that Tapejara wellnhoferi was likely primarily frugivorous, although it may also have opportunistically fed on small animals.
One fossil specimen records the remains of two similarly sized young individuals preserved within the same rock. This does not necessarily prove that they lived gregariously, but it does suggest that this pterosaur may not always have been solitary, and that individuals may at times have shared habitats or perching sites.
（Author: Shui-Ye You）
References
Chatterjee S and Templin RJ. (2013). The Flight Dynamics of Tapejara, a Pterosaur From the Early Cretaceous of Brazil with a Large Cranial Crest. Acta Geologica Sinica.
Eck K. (2011). On the osteology of Tapejara wellnhoferi KELLNER 1989 and the first occurrence of a multiple specimen assemblage from the Santana Formation, Araripe Basin, NE-Brazil. Swiss Journal of Palaeontology.
Pêgas RV et al. (2016). A Basal Tapejarine (Pterosauria; Pterodactyloidea; Tapejaridae) from the Crato Formation, Early Cretaceous of Brazil. PLoS One.
Zhou CF et al. (2022). A new wing skeleton of the Jehol tapejarid Sinopterus and its implications for ontogeny and paleoecology of the Tapejaridae. Scientific Reports.
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