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
Anura
indet.
(
Fig. 10
)
DESCRIPTION
Despite a swampy paleoenvironment that might be suitable for their occurrence and preservation, anurans are relatively scarce among the microvertebrate material from Angeac-Charente. In Angeac-Charente, anurans are represented by isolated, fragmentary bones, such as fused zeugopods (
Fig. 10A, B
) and urostyles (
Fig. 10C, D
)
Among fused zeugopods, some are sufficiently well preserved to allow their identification.For instance, the general shape and length (even if the proximal part is missing) of specimen ANG M-63 (
Fig. 10A, B
), as well as several other features, allow its identification as a tibiofibula (
Thomas 1996
): presence of a tibiofibular groove, deeper on the anterior face, between the fused zeugopod, and presence of a tibial crest on the anterior face (
Fig. 10A
). Among well-known Early Cretaceous anuran families are the
Alytidae
(= “
Discoglossidae
”), but within this family, the tibia and fibula remain unfused (
Roček 2000
), unlike the Angeac-Charente specimen.
FIG. 9. — Albanerpetontid remains from Angeac-Charente:
A
,
B
, left dentary of
Albanerpetontidae
indet. (ANG M-101) in lingual (
A
) and dorsal (
B
) views;
C
, premaxillary of
Albanerpetontidae
indet. (ANG M-102) in ventrolingual view;
D
,
E
, left maxillary of
Albanerpetontidae
indet. (ANG M-51) in labial (
D
) and lingual (
E
) views;
F
,
G
, dentary fragment of
Albanerpetontidae
indet. (ANG M-35) in labial view showing foramina discussed in the text (
F
) and lingual (
G
) view;
H
, distal end of a left humerus of
Albanerpetontidae
indet. (ANG M-36) in ventral view;
I -K
, dorsal vertebra of
Albanerpetontidae
indet. (ANG M-103) in dorsal (
I
), anterior (
J
) and lateral (
K
) views. Scale bars: A-E, H-K, 400 µm; F, G, 1 mm.
FIG. 10. — Anuran remains from Angeac-Charente:
A
,
B
, right tibiofibular of
Anura
indet.(ANG M-63) in anterior (
A
) and posterior (
B
) views;
C
,
D
, urostyle of
Anura
indet. (ANG M- 64) in dorsal (
C
) and ventral (
D
) views. Scale bar represents:
A
,
B
, 5 mm;
C
,
D
, 2 mm.
The specimen ANG M-64 (
Fig. 10C, D
) bears two broad and flattened articular facets anteriorly, and a small crest arises from its dorsal face. Four weakly marked ridges can be seen alongside this small crest, two on each side (
Fig. 9C
). This morphology identifies it as a urostyle. To date, incompleteness of the material limits comparisons with other Mesozoic anurans.