Agaresuchus

Agaresuchus Temporal range: Late Cretaceous, Campanian–Maastrichtian PreꞒ Ꞓ O S D C P T J K Pg N
Holotype skull of A. subjuniperus
Skull of A. fontisensis
Scientific classification
Domain:	Eukaryota
Kingdom:	Animalia
Phylum:	Chordata
Class:	Reptilia
Clade:	Archosauria
Clade:	Pseudosuchia
Clade:	Crocodylomorpha
Clade:	Crocodyliformes
Clade:	Neosuchia
Clade:	Eusuchia
Clade:	† Allodaposuchidae
Genus:	† Agaresuchus Narváez et al., 2016
Type species
†Agaresuchus fontisensis Narváez et al., 2016
Species
†A. fontisensisNarváez et al., 2016 (type †Agaresuchus subjuniperus(Puértolas et al., 2013)

Agaresuchus is an extinct genus of allodaposuchid eusuchian crocodylomorph from the Late Cretaceous (Campanian-Maastrichtian) of Spain. It includes two species, the type species A. fontisensis, and A. subjuniperus, which was originally named as a species of the related genus Allodaposuchus . However, it has been proposed that both species may instead belong to the genus Allodaposuchus.

Discovery and naming

The genus Agaresuchus was named in 2016 upon the discovery of Agaresuchus fontisensis . Allodaposuchus subjuniperus, discovered in 2013 and originally classified as a new and second species of Allodaposuchus , was then reassigned to Agaresuchus. ^[1] It is based on the holotype skull, specimen MPZ 2012/288.

A. subjuniperus was named in 2013 on the basis of a skull from the late Maastrichtian-aged Conquès Formation, part of the Tremp Group, in the province of Huesca, Spain. The skull was found underneath a juniper tree whose roots had grown between the bones, hence the specific name subjuniperus or "under juniper" in Latin. ^[2]

In 2016, the new genus and species Agaresuchus fontisensis was discovered and described. ^[1] The genus name refers to the demon Agares, depicted by Johann Weyer as an old man riding a crocodile. The specific name was named from the Lo Hueco fossil site in Fuentes, Cuenca, Spain; fontes is the Latin name of Fuentes.

Description

The two species differ in traits such as the shape of the snout (elongated in the former, short in the latter); the shape of the premaxilla (longer than wide compared to wider than long); the number of maxillary tooth sockets (15 compared to 14); the shape of the eye sockets (large and round compared to short and crescent-shaped); the width between the eyes (narrow compared to characteristically broad); and characteristics of the palate and nasal bones. ^{[1] [3]}

Classifiation

Agaresuchus was considered to be sufficiently distinct from the eastern European Allodaposuchus precedens to warrant a new genus. ^[1]

Alternatively, a 2021 phylogenetic analysis considering additional postcranial material recovered Allodaposuchus as paraphyletic with respect to Agaresuchus and Lohuecosuchus , and suggested that both A. fontisensis and A. subjuniperus belong within the genus Allodaposuchus proper, which would render Agaresuchus as a junior synonym of Allodaposuchus. ^[3] The cladogram from Blanco's 2021 study is shown below: ^[3]

Allodaposuchidae	Arenysuchus gascabadiolorum Allodaposuchus precedens Allodaposuchus iberoarmoricanus Allodaposuchus subjuniperus Allodaposuchus palustris Allodaposuchus hulki Agaresuchus fontisensis Lohuecosuchus mechinorum Lohuecosuchus megadontos

References

1. Narváez, I.; Brochu, C.A.; Escaso, F.; Pérez-García, A.; Ortega, F. (2016). "New Spanish Late Cretaceous eusuchian reveals the synchronic and sympatric presence of two allodaposuchids". Cretaceous Research. 65: 112–125. doi: 10.1016/j.cretres.2016.04.018 .
2. Puértolas-Pascual, E.; Canudo, J.I.; Moreno-Azanza, M. (2014). "The eusuchian crocodylomorph Allodaposuchus subjuniperus sp. nov., a new species from the latest Cretaceous (upper Maastrichtian) of Spain". Historical Biology. 26 (1): 91–109. doi:10.1080/08912963.2012.763034. S2CID   85004774.
3. Blanco, A. (2021). "Importance of the postcranial skeleton in eusuchian phylogeny: Reassessing the systematics of allodaposuchid crocodylians". PLOS ONE. 16 (6): e0251900. Bibcode:2021PLoSO..1651900B. doi: 10.1371/journal.pone.0251900 . PMC   8189472 . PMID   34106925.