Update on the Cenomanian vertebrates from Algora (Guadalajara, Spain):new data on the faunal transition between the Early and the Late Cretaceous of Europe
Abstract
The largest concentration of vertebrate macroremains for the Cenomanian of south-western
Europe has been recognized at the palaeontological area of Algora (Guadalajara Province, central
Spain). The study of the taxa identified there provided new information about the palaeobiogeography
and temporal distributions of some lineages, and increased knowledge about the poorly-
known transition between the Lower and the Upper Cretaceous faunas in Europe. The presence
of eight taxa was confirmed there: the lepisosteoid fish Obaichthys africanus; the helochelydrid
turtle aff. Plastremys lata; the bothremydid turtle Algorachelus peregrina; an indeterminate elasmosaurid
plesiosaur; a non-eusuchian neosuchian and a eusuchian crocodyliform; an indeterminate
lithostrotian titanosaur; and an indeterminate theropod probably belonging to Abelisauridae.
Recent fieldwork campaigns, performed in 2019 and 2021, provided more than 1,200 new vertebrate
remains, including those of clades poorly represented so far, as well as others hitherto
unknown at this site. Therefore, the faunal list can be remarkably increased. In this sense, several
taxa of Osteichthyes have been found, and chondrichthyan remains are also recognized there for
the first time. New remains of crocodyliforms, theropods and sauropods allow to analyze, in more
detail, the systematic attribution of the representatives of these lineages present in Algora. Not
only new relevant specimens of helochelydrids and bothremydids stand out among the numerous
finds of turtles (which allow a better understanding of the anatomy of the represented species),
but especially the discovery of the partial skeleton of a relatively large cryptodiran sea turtle
(including, among other elements, the carapace, with more than 1 meter in length, and the skull).
In addition, other lineages hitherto unrecognized at this fossiliferous locality, such as a squamate
with aquatic affinities, are identified. The main novelties in knowledge about the Cenomanian vertebrate
fauna of Algora are presented here, and the palaeobiogeographical implications of several
of the new finds are discussed.
Origin : Files produced by the author(s)