Eucalliaxiopsis Sakai, 2011

Klompmaker, Adiël A., Martin, P. George, Hyžný, Matúš, Bowman, Andrew R., Phillips, George E. & Portell, Roger W., 2025, Systematics, biodiversity, and paleoecology of an early Danian decapod crustacean assemblage from Alabama, United States, Geodiversitas 47 (13), pp. 577-622 : 587

publication ID

https://doi.org/10.5252/geodiversitas2024v47a13

publication LSID

urn:lsid:zoobank.org:pub:F5144147-C045-48FD-8128-7F822CDE6B18

DOI

https://doi.org/10.5281/zenodo.17182714

persistent identifier

https://treatment.plazi.org/id/F77987B8-FFBF-FF9E-1315-C8B1AB3FFEE8

treatment provided by

Plazi

scientific name

Eucalliaxiopsis Sakai, 2011
status

 

Genus Eucalliaxiopsis Sakai, 2011 View in CoL

TYPE SPECIES. — Eucalliax cearaensis Rodrigues & Manning, 1992 , by original designation and monotypy.

INCLUDED FOSSIL SPECIES. — Eucalliaxiopsis alabamensis ( Rathbun, 1935a) n. comb.; E. pseudorakosensis (Lőrenthey in Lőrenthey & Beurlen, 1929).

DIAGNOSIS. — See Sakai (2011: 503, 504).

REMARKS

The assignment of Callianassa alabamensis Rathbun, 1935 , to Eucalliaxiopsis is based on the combination of the following characters: a subquadrate manus, a triangular fixed finger with an oblique longitudinal ridge, and a smooth lower margin of cheliped merus. The oblique longitudinal ridge is also present in Calliaxina Ngoc-Ho, 2003 (Hyžný 2012; Poore 2021), but it is accompanied by a lateral concavity in the minor chela in this genus (Hyžný 2012), a character which is not identified in C. alabamensis . In Calliaxina , the lower margin of the cheliped merus has denticles ( Poore 2021), whereas it is smooth in C. alabamensis . The observed variation of two morphotypes of cheliped dactylus in C. alabamensis corresponds to differences between major and minor claws as exemplified in extant species of Eucalliaxiopsis ( Poore 2021) .

At least some fossil species of Eucalliax Manning & Felder, 1991 , as listed by Schweitzer et al. (2010) and Hyžný & Klompmaker (2015), probably belong to Eucalliaxiopsis . This is because they were assigned to Eucalliax largely based on similarities with some extant species, previously classified within Eucalliax . Recent revisions ( Poore et al. 2019; Robles et al. 2020; Poore 2021) recognized the genus Eucalliax to be monotypic, with the only extant representative being its type species, E. quadracuta ( Biffar, 1970) , while the species previously treated under Eucalliax were reassigned to other eucalliacid genera. In this respect, Hyžný & Dulai (2021) reassigned Eucalliax pseudorakosensis (Lőrenthey in Lőrenthey & Beurlen, 1929) from the Miocene of Central Europe to Eucalliaxiopsis . Other fossil species of Eucalliax are still pending revision.

Kingdom

Animalia

Phylum

Arthropoda

Class

Malacostraca

Order

Decapoda

InfraOrder

Axiidea

Family

Eucalliacidae

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