New smallest specimen of the pterosaurPteranodonand ontogenetic niches in pterosaurs

Abstract

A new juvenile specimen ofPteranodonfrom the Smoky Hill Chalk Member of the Niobrara Formation of western Kansas had an estimated wingspan in life of 1.76 m, ~45% smaller than the smallest previously known specimens, but does not differ in morphology from larger specimens. Its presence indicates that juveniles were capable of flying long distances, so it falsifies the interpretation ofPteranodonas growing rapidly to adult size under parental care before flying. Instead juveniles were precocial, growing more slowly to adult size while flying and feeding independently for several years before going to sea. Because juveniles are otherwise unknown in the Smoky Hill Chalk Member, they must have occupied different environments and ecological niches than adults; thusPteranodonexhibited ontogenetic niches. Evidence is presented that most other pterosaurs (e.g.,Rhamphorhynchus,Pterodactylus,Anhanguera) also exhibited various ontogenetic niches, which, along with their large body size, suggests that pterosaur taxonomic diversity was rather low, like that of crocodilians.

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

“… 32 ), but are not exhibited by birds 8 . DMTA thus provides direct evidence of ontogenetic dietary shifts in a pterosaur, and supports the hypothesis that pterosaur life-histories were more like those of reptiles than birds or bats 6 – 8 , 30 .

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“…While this might indicate finer niche partitioning between Solnhofen pterosaurs, it is also likely that these species were not typical members of the community as they are relatively rare (<5 specimens in both cases). Ontogenetic dietary shifts have been suggested for several pterosaurs [6][7][8]30,31 but the hypothesis lacks evidential support. In our study, the dietary separation of Rhamphorhynchus specimens along PC 1 correlates with specimen size (reptile PCA; lower jaw length; r s = −0.6044, P = 0.0221; Fig.…”

“…Ontogenetic dietary shifts have been suggested for several pterosaurs 6 – 8 , 30 , 31 but the hypothesis lacks evidential support. In our study, the dietary separation of Rhamphorhynchus specimens along PC 1 correlates with specimen size (reptile PCA; lower jaw length; r s = −0.6044, P = 0.0221; Fig.…”

“…As important components of Mesozoic biotas 4 , robust reconstructions of pterosaur diets are thus crucial not only for understanding the ecological roles they performed within Mesozoic food webs, but for helping address broader ecological and evolutionary debates that enhance our understanding of Mesozoic ecosystems. Key debates include: whether sympatric species of pterosaur competed for, or partitioned, food resources 5 ; whether ontogenetic stages of a single species competed for, or partitioned, resources and thus had life-histories more similar to those of extant birds or non-avian reptiles 6 – 8 ; and what impact the emergence and radiation of birds had on pterosaur dietary evolution 9 , and vice versa.…”

A new wing skeleton of &lt;i&gt;Forfexopterus&lt;/i&gt; (Pterosauria: Ctenochasmatidae) from the Early Cretaceous Jehol Biota reveals a developmental variation

“…As aforementioned, SDUST-V1003 represents a mature individual, evident by the fused scapulocoracoid and the syncarpals, the extensor tendon process fused with the first wing phalanx, and the well-ossified humerus. Based on Bennett's (1993Bennett's ( , 2018 size-independent criteria in the pterosaur ontogeny, these features indicate that SDUST-V1003 is at the highest stage of the maturity (adult). In contrast, the type specimen (HM V20) is immature (subadult) and lacks all of these ossified features, except for the ossified syncarpals.…”