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Papers by Eduardo Puértolas Pascual

Th e vertebrate fossil record in the Early Cretaceous of Aragón was concentrated in the lower Bar... more Th e vertebrate fossil record in the Early Cretaceous of Aragón was concentrated in the lower Barremian, contrasting with other rich sectors of the Iberian Range as in Las Hoyas (upper Barremian, Cuenca) or Morella (lower Aptian, Castellón). However, recent discoveries at the Escucha Formation have notably improved the lower Albian fossil record .Th e recovery of neosuchian crocodylomorphs in the coal mine Corta Barrabasa and Mina Santa Maria (Escucha Formation, lower Albian) located in the municipalities of Andorra and Ariño (Teruel) shall help to complete the crocodylomorph fossil assemblages for this time interval .

During the Late Cretaceous, crocodylomorph faunas were highly diverse, including dyrosaurids, pho... more During the Late Cretaceous, crocodylomorph faunas were highly diverse, including dyrosaurids, pholidosaurids, notosuchians, some relics of typical faunas of the Early Cretaceous such as atoposaurids and goniopholidids, and taxa of the clade Eusuchia, from which diverged living crocodylians. Eusuchians are composed of several stem taxa and the crown Crocodylia containing the three major lineages Crocodyloidea, Alligatoroidea and Gavialoidea . Th e earliest members of Eusuchia and the clade Crocodylia originated in the northern continents, North America and Europe, and had a prolonged radiation between the Late Cretaceous and the Eocene. In the Late Cretaceous, members of Eusuchia representing its early radiation occurred in Europe (Narváez & Ortega, 2011). Among them there was the sister taxa of Crocodylia, such as Hylaeochampsidae (e.g. the English Hylaeochampsa vectiana, the Hungarian Iharkutosuchus makadii, the Romanian Acynodon adriaticus and the Iberian Acynodon iberoccitanus) and the genus Allodaposuchus (according to . Th is later genus is composed of the following species: the Romanian Allodaposuchus precedens, the French Allodaposuchus cf. A. precedens, and the Spanish Allodaposuchus subjuniperus. Among the crown taxa there were basal crocodyloids as the Spanish Arenysuchus gascabadiolorum and basal alligatoroids as the French Massaliasuchus affl uvelensis and the Spanish Musturzabalsuchus buff etauti, but probably these taxa are more related to the stem group than with the crown group and a new classifi cation should be performed when more complete specimens will be recovered. In the Late Cretaceous of France, Netherlands and Ucrania (Crimea) several species of basal gavialoids attributed to the genus Th oracosaurus were described.

Background The earliest crocodylians are known primarily from the Late Cretaceous of North Am... more Background

The earliest crocodylians are known primarily from the Late Cretaceous of North America and Europe. The representatives of Gavialoidea and Alligatoroidea are known in the Late Cretaceous of both continents, yet the biogeographic origins of Crocodyloidea are poorly understood. Up to now, only one representative of this clade has been known from the Late Cretaceous, the basal crocodyloid Prodiplocynodon from the Maastrichtian of North America.

Methodology/Principal Findings

The fossil studied is a skull collected from sandstones in the lower part of the Tremp Formation, in Chron C30n, dated at −67.6 to 65.5 Ma (late Maastrichtian), in Arén (Huesca, Spain). It is located in a continuous section that contains the K/P boundary, in which the dinosaur faunas closest to the K/P boundary in Europe have been described, including Arenysaurus ardevoli and Blasisaurus canudoi. Phylogenetic analysis places the new taxon, Arenysuchus gascabadiolorum, at the base of Crocodyloidea.

Conclusions/Significance

The new taxon is the oldest crocodyloid representative in Eurasia. Crocodyloidea had previously only been known from the Palaeogene onwards in this part of Laurasia. Phylogenetically, Arenysuchus gascabadiolorum is situated at the base of the first radiation of crocodyloids that occurred in the late Maastrichtian, shedding light on this part of the cladogram. The presence of basal crocodyloids at the end of the Cretaceous both in North America and Europe provides new evidence of the faunal exchange via the Thulean Land Bridge during the Maastrichtian.

Abstracts by Eduardo Puértolas Pascual

Phylogenetic analysis of Allodaposuchus

Th e vertebrate fossil record in the Early Cretaceous of Aragón was concentrated in the lower Bar... more Th e vertebrate fossil record in the Early Cretaceous of Aragón was concentrated in the lower Barremian, contrasting with other rich sectors of the Iberian Range as in Las Hoyas (upper Barremian, Cuenca) or Morella (lower Aptian, Castellón). However, recent discoveries at the Escucha Formation have notably improved the lower Albian fossil record .Th e recovery of neosuchian crocodylomorphs in the coal mine Corta Barrabasa and Mina Santa Maria (Escucha Formation, lower Albian) located in the municipalities of Andorra and Ariño (Teruel) shall help to complete the crocodylomorph fossil assemblages for this time interval .

During the Late Cretaceous, crocodylomorph faunas were highly diverse, including dyrosaurids, pho... more During the Late Cretaceous, crocodylomorph faunas were highly diverse, including dyrosaurids, pholidosaurids, notosuchians, some relics of typical faunas of the Early Cretaceous such as atoposaurids and goniopholidids, and taxa of the clade Eusuchia, from which diverged living crocodylians. Eusuchians are composed of several stem taxa and the crown Crocodylia containing the three major lineages Crocodyloidea, Alligatoroidea and Gavialoidea . Th e earliest members of Eusuchia and the clade Crocodylia originated in the northern continents, North America and Europe, and had a prolonged radiation between the Late Cretaceous and the Eocene. In the Late Cretaceous, members of Eusuchia representing its early radiation occurred in Europe (Narváez & Ortega, 2011). Among them there was the sister taxa of Crocodylia, such as Hylaeochampsidae (e.g. the English Hylaeochampsa vectiana, the Hungarian Iharkutosuchus makadii, the Romanian Acynodon adriaticus and the Iberian Acynodon iberoccitanus) and the genus Allodaposuchus (according to . Th is later genus is composed of the following species: the Romanian Allodaposuchus precedens, the French Allodaposuchus cf. A. precedens, and the Spanish Allodaposuchus subjuniperus. Among the crown taxa there were basal crocodyloids as the Spanish Arenysuchus gascabadiolorum and basal alligatoroids as the French Massaliasuchus affl uvelensis and the Spanish Musturzabalsuchus buff etauti, but probably these taxa are more related to the stem group than with the crown group and a new classifi cation should be performed when more complete specimens will be recovered. In the Late Cretaceous of France, Netherlands and Ucrania (Crimea) several species of basal gavialoids attributed to the genus Th oracosaurus were described.

Background The earliest crocodylians are known primarily from the Late Cretaceous of North Am... more Background

The earliest crocodylians are known primarily from the Late Cretaceous of North America and Europe. The representatives of Gavialoidea and Alligatoroidea are known in the Late Cretaceous of both continents, yet the biogeographic origins of Crocodyloidea are poorly understood. Up to now, only one representative of this clade has been known from the Late Cretaceous, the basal crocodyloid Prodiplocynodon from the Maastrichtian of North America.

Methodology/Principal Findings

The fossil studied is a skull collected from sandstones in the lower part of the Tremp Formation, in Chron C30n, dated at −67.6 to 65.5 Ma (late Maastrichtian), in Arén (Huesca, Spain). It is located in a continuous section that contains the K/P boundary, in which the dinosaur faunas closest to the K/P boundary in Europe have been described, including Arenysaurus ardevoli and Blasisaurus canudoi. Phylogenetic analysis places the new taxon, Arenysuchus gascabadiolorum, at the base of Crocodyloidea.

Conclusions/Significance

The new taxon is the oldest crocodyloid representative in Eurasia. Crocodyloidea had previously only been known from the Palaeogene onwards in this part of Laurasia. Phylogenetically, Arenysuchus gascabadiolorum is situated at the base of the first radiation of crocodyloids that occurred in the late Maastrichtian, shedding light on this part of the cladogram. The presence of basal crocodyloids at the end of the Cretaceous both in North America and Europe provides new evidence of the faunal exchange via the Thulean Land Bridge during the Maastrichtian.

Phylogenetic analysis of Allodaposuchus