Vertebrate paleobiodiversity of the Early Cretaceous (Berriasian) Angeac-Charente Lagerstätte (southwestern France): implications for continental faunal turnover at the J / K boundary
Author
Allain, Ronan
Author
Vullo, Romain
Author
Rozada, Lee
Author
Anquetin, Jérémy
Author
Bourgeais, Renaud
Author
Goedert, Jean
Author
Lasseron, Maxime
Author
Martin, Jeremy E.
Author
Pérez-García, Adán
Author
Fabrègues, Claire Peyre De
Author
Royo-Torres, Rafael
Author
Augier, Dominique
Author
Bailly, Gilles
text
Geodiversitas
2022
2022-07-21
44
25
683
752
journal article
107849
10.5252/geodiversitas2022v44a25
d0184974-bea3-4f97-a2f8-98887ec4f87e
1638-9395
6902033
urn:lsid:zoobank.org:pub:EA12DCB7-A5BE-4763-B805-25087EBD726D
Megalosauridae
? indet.
(
Fig. 28
K-N)
DESCRIPTION
All the large (>
3 cm
) blade-like theropod teeth found at Angeac-Charente are tentatively referred to a single taxon, although two tooth morphotypes are present. The first morphotype probably corresponds to mesial teeth (
Fig. 28
K-M), the crown of which are slender and more elongated than in lateral teeth (
Fig. 28N
). The crown height ratio (
Hendrickx
et al.
2015a
) ranges between 1.91 (ANG M-121) for a lateral tooth and 2.43 for a mesial one (ANG 17-5650). Apart from that, the teeth have the same characters. They are strongly compressed labiolingually. The mesial margin is convex and the distal margin is only slightly concave. Both the distal and mesial carinae are denticulate, but the latter only occurs on the apical half to one third of the crown. The carinae are centrally positioned on both the mesial and distal margins of crowns. There are 12 (ANG 17-5650) to 18 (ANG M-121) denticles per
5 mm
along the mesial carinae, and 12 to 15 along the distal carinae at two thirds of the crown height. The denticles are longer mesiodistally than they are basoapically high, and they have a horizontal subrectangular outline. Interdental sulci are present. The enamel is transversely wrinkled and both transverse and marginal undulations are present (
Hendrickx
et al.
2015a
).
Teeth of large carnivorous dinosaurs, morphologically very close to those of Angeac-Charente, have been reported from the Tithonian of Chassiron and from the Purbeckian of
England
. The first have been referred with caution to
Megalosauridae (
Vullo
et al.
2014
)
, while the latter have been alternately referred to
Megalosauridae
or Allosauroidea (see
Milner 2002
). All dental characters described above have been recognized in
Megalosauridae (
Hendrickx
et al.
2015b
)
, and we tentatively refer the large dinosaur teeth of Angeac-Charente to this group, but an assignement to another basal tetanuran clade cannot be definitively excluded.