[dinosaur] Crocodylomorph palaeobiodiversity from Late Jurassic Lourinha Formation of Portugal

Ben Creisler
[email protected]

A new paper:

Alexandre R. D. Guillaume, Miguel Moreno-Azanza, Eduardo Puértolas-Pascual
&  Octávio Mateus (2019)
Palaeobiodiversity of crocodylomorphs from the Lourinhã Formation based on
the tooth record: insights into the palaeoecology of the Late Jurassic of
Portugal.
Zoological Journal of the Linnean Society, zlz112 (advance online
publication)
doi: https://urldefense.proofpoint.com/v2/url?u=https-3A__doi.org_10.1093_zoolinnean_zlz112&d=DwIFaQ&c=clK7kQUTWtAVEOVIgvi0NU5BOUHhpN0H8p7CSfnc_gI&r=Ry_mO4IFaUmGof_Yl9MyZgecRCKHn5g4z1CYJgFW9SI&m=M-eHZk6UmChKg98PWLzONibKz_uwteo4swqXXv96WIY&s=t_mIuJtxMRmA0JMNMOauwvQ816tvvgZxGw81oR_DGp8&e= 
https://urldefense.proofpoint.com/v2/url?u=https-3A__academic.oup.com_zoolinnean_advance-2Darticle-2Dabstract_doi_10.1093_zoolinnean_zlz112_5648910&d=DwIFaQ&c=clK7kQUTWtAVEOVIgvi0NU5BOUHhpN0H8p7CSfnc_gI&r=Ry_mO4IFaUmGof_Yl9MyZgecRCKHn5g4z1CYJgFW9SI&m=M-eHZk6UmChKg98PWLzONibKz_uwteo4swqXXv96WIY&s=yGhY8R-upT871aDr37Yaj5knEX83XNWuy0Q9IMUFYmA&e= 



Crocodylomorphs were a diverse clade in the Late Jurassic of Portugal, with
six taxa reported to date. Here we describe 126 isolated teeth recovered by
screen-washing of sediments from Valmitão (Lourinhã, Portugal, late
Kimmeridgian-Tithonian), a vertebrate microfossil assemblage in which at
least five distinct crocodylomorph taxa are represented. Ten morphotypes
are described and attributed to five clades (Lusitanisuchus, Atoposauridae,
Goniopholididae, Bernissartiidae and an undetermined mesoeucrocodylian).
Four different ecomorphotypes are here proposed according to ecological
niches and feeding behaviours: these correspond to a diet based on
arthropods and small vertebrates (Lusitanisuchus and Atoposauridae), a
generalist diet (Goniopholididae), a durophagous diet (Bernissartiidae) and
a carnivorous diet. Lusitanisuchus mitracostatus material from Guimarota is
here redescribed to achieve a better illustration and comparison with the
new material.

This assemblage shares similar ecomorphotypes with other Mesozoic
west-central European localities, where a diversity of crocodylomorphs
lived together, avoiding direct ecological competition through niche
partitioning. The absence of large marine crocodylomorphs, present in other
contemporaneous assemblages, is here interpreted as evidence that the
Valmitão assemblage was deposited in a freshwater environment, although
sample bias cannot be completely ruled out. These affinities are further
supported by the presence of lanceolate and leaf-shaped teeth associated
with continental clades.

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