Lohuecosuchus

Lohuecosuchus (meaning "Lo Hueco crocodile") is an extinct genus of allodaposuchid eusuchian crocodylomorph that lived during the Late Cretaceous (late Campanian to early Maastrichtian) in what is now Spain and southern France.

Lohuecosuchus Temporal range: Late Cretaceous: Campanian–Maastrichtian, 77.9–69 Ma[1] PreꞒ Ꞓ O S D C P T J K Pg N
Skull and mandible of Lohuecosuchus megadontos
Scientific classification
Domain:	Eukaryota
Kingdom:	Animalia
Phylum:	Chordata
Class:	Reptilia
Clade:	Archosauria
Clade:	Pseudosuchia
Clade:	Crocodylomorpha
Clade:	Crocodyliformes
Clade:	Eusuchia
Clade:	†Allodaposuchidae
Genus:	†Lohuecosuchus Narváez et al., 2015
Type species
†Lohuecosuchus megadontos Narváez et al. 2015
Species
†L. mechinorum Narváez et al. 2015 †L. megadontos Narváez et al. 2015

Description

The anatomy of the endocranium (braincase) of L. megadontos was found to be similar to crown-crocodylians, revealing that the acute sense of olfaction and low frequency hearing found in living crocodylians likely originated along the stem-line.^[2]

Classification

Lohuecosuchus is a member of the clade Allodaposuchidae, a group of eusuchians that lived in southern Europe during the Late Cretaceous.^[3] Two species of Lohuecosuchus were described in 2015. The type species, Lohuecosuchus megadontos, was recovered from the Lo Hueco fossil site of the Villalba de la Sierra Formation in the municipality of Fuentes, Cuenca Province at Castilla-La Mancha of central Spain. The species name megadontos is composed of the Greek words "mega" (meaning big) and "odon" (meaning tooth), in reference to the relatively large size of the teeth.^[3] The second species, Lohuecosuchus mechinorum, was found at the Fox-Amphoux fossil site of the Grès à Reptiles Formation in the Department of Var in southeastern France, and was named after the discoverers of the holotype, Patrick and Annie Mechin.^[3]

Lohuecosuchus was both synchronic and sympatric (lived at the same time and place) with another allodaposuchid species, Agaresuchus fontisensis.^[4] Lohuecosuchus is also closely related to Allodaposuchus, another genus from southern Europe that includes several species.

However, a 2021 phylogenetic analysis considering additional postcranial material recovered Allodaposuchus as paraphyletic with respect to Agaresuchus and Lohuecosuchus, and suggested that both Agaresuchus and Lohuecosuchus belong within the genus Allodaposuchus proper, which would render them as junior synonyms of Allodaposuchus.^[5] The cladogram from Blanco's 2021 study is shown below:^[5]

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

References

1. Rio, Jonathan P.; Mannion, Philip D. (6 September 2021). "Phylogenetic analysis of a new morphological dataset elucidates the evolutionary history of Crocodylia and resolves the long-standing gharial problem". PeerJ. 9: e12094. doi:10.7717/peerj.12094. PMC 8428266. PMID 34567843.
2. Serrano-Martanez, A.; Knoll, F.; Narvaez, I.; Lautenschlager, S.; Ortega, F. (2018). "Inner skull cavities of the basal eusuchian Lohuecosuchus megadontos (Upper Cretaceous, Spain) and neurosensorial implications". Cretaceous Research. 93: 66–77. doi:10.1016/j.cretres.2018.08.016.
3. Narváez, I.; Brochu, C.A.; Escaso, F.; Pérez-García, A.; Ortega, F. (2015). "New crocodyliforms from southwestern Europe and definition of a diverse clade of european Late Cretaceous basal eusuchians". PLOS ONE. 10 (11): e0140679. Bibcode:2015PLoSO..1040679N. doi:10.1371/journal.pone.0140679. PMC 4633049. PMID 26535893.
4. Narvaez, I.; Brochu, C.A.; Escaso, F.; Perez-Garcia, 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.
5. 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.