Aymberedactylus

{{short description|Genus of tapejarid pterosaur from the Early Cretaceous}}

{{speciesbox

| fossil_range = Early Cretaceous, {{fossilrange|108}}

| genus = Aymberedactylus

| image = Aymberedactylus.PNG

| image_caption = Holotype mandible

| parent_authority = Pêgas et al., 2016

| species = cearensis

| authority = Pêgas et al., 2016

}}

Aymberedactylus (meaning "small lizard finger") is a genus of tapejarid pterosaur from the Early Cretaceous Crato Formation of Brazil.{{cite journal | last1 = Pêgas | first1 = R.V. | last2 = Leal | first2 = M.E.d. | last3 = Kellner | first3 = A.W.A. | title = A Basal Tapejarine (Pterosauria; Pterodactyloidea; Tapejaridae) from the Crato Formation, Early Cretaceous of Brazil. | journal = PLOS ONE | date = 2016 | volume = 11 | issue = 9 | page = e0162692 | doi = 10.1371/journal.pone.0162692 | pmid=27655346 | pmc=5031394| bibcode = 2016PLoSO..1162692P | doi-access = free }} It contains a single species, A. cearensis.

Discovery and naming

The holotype specimen of Aymberedactylus, MN 7596-V, is a nearly complete mandible preserved in three dimensions. It was discovered in the Aptian-Albian Crato Formation, a konservat-lagerstätte well known for its exquisite preservation of fossils,{{cite book |editor= Martill, D.M. | last1 = Unwin | first1 = D.M. | last2 = Martill | first2 = D.M. | title = The Crato Fossil Beds of Brazil: Window into an Ancient World |url= https://archive.org/details/cratofossilbedsb00mart |url-access= limited | date = 2007 | chapter = Pterosaurs of the Crato Formation. | publisher = Cambridge University Press | location = Cambridge | pages = [https://archive.org/details/cratofossilbedsb00mart/page/n492 475]–524 | isbn = 978-0-521-85867-0 }} and it was described in 2016.

The name Aymberedactylus is derived from the Tupi word {{lang|tpn|aymbere}} ("small lizard") and Greek {{Transliteration|el|daktylos}} ("finger"), and the specific name refers to the Brazilian state of Ceará, which it was discovered in.

Description

File:Mandibular symphysis of Aymberedactylus.PNG

Aymberedactylus can be identified as a tapejarine tapejarid from the holotypic jawbone due to its toothlessness, slightly downturned dentary symphysis which accounts for half of the total length of the jaw, and a small crest on the bottom of the dentary (which was incompletely preserved). Small neurovascular foramina on the symphysis indicates the likely presence of a horned sheath over the tip of the jaw, which is also seen in Tupandactylus. The preserved portion is {{convert|270|mm}} long.

It can be distinguished from other pterosaurs by a long retroarticular process (a process to which the depressor mandibulae muscle attaches, implying that Aymberedactylus had good control over the movement of its jaw bones) and a small fossa, or depression, with a roughened bone texture on the splenial bone. In addition, Aymberedactylus shows a unique combination of traits: the shelf on the dentary symphysis is deep, the dorsal rim of the symphysis is concave, the jaw is relatively wide, the dentary fossa is short and shallow (which indicates a relatively weak bite), and the mandibular rami form a very large angle with the symphysis. These traits are a unique combination of basal and derived characteristics within Tapejaridae.

The preserved specimen of Aymberedactylus would have had a wingspan of approximately {{convert|2|m}}, typical of tapejarids. Judging by how the bones in its skull were not yet entirely fused, it was likely a subadult.