Parahyas, Charbonnier & Garassino & Pasini & Chény, 2024

Charbonnier, Sylvain, Garassino, Alessandro, Pasini, Giovanni & Chény, Cédric, 2024, Review of brachyuran crabs from the late Miocene (Messinian) of Oran, Algeria, Geodiversitas 46 (2), pp. 13-29 : 19

Parahyas n. gen.

urn:lsid:zoobank.org:act:B38E2FCA-0FC0-43E8-99A4-3F94395BEA5E

ETYMOLOGY. — A combination between Para (Latin: similar to) and the extant genus Hyas Leach, 1814 . The gender of the genus is masculine.

TYPE SPECIES. — Hyas oranensis Van Straelen, 1937 .

DIAGNOSIS. — Carapace pyriform; orbit composed of supraorbital rim and widely cup-shaped postorbital spine bearing marginal spines; inflated branchial regions with posterolateral margin bearing row of tubercles; intestinal region protruding distally beyond and under branchial regions; urogastric and cardiac regions limited by deep branchiocardiac groove.

DISCUSSION

Parahyas n. gen. is assigned to the Oregoniidae based upon the widely cup-shaped postorbital spine, which is well visible in several extant representatives such as Hyas coarctatus Leach, 1815 and H. ursinus Rathbun, 1924 . Parahyas n. gen. differs from Oregonia , Chionoecetes , Macroregonia by the presence of widely cup-shaped postorbital spine (absent in all these genera). Parahyas n. gen. differs from Hyas by the presence of a row of large tubercles extending along the entire length of the posterolateral margin (versus sometimes scarce small tubercles along the margin in Hyas ), dorsal surface of carapace covered by small tubercles arranged uniformly (versus scattered granules and tubercles of varying size in Hyas ), and gastric, urogastric, and cardiac regions without median raised tubercles (versus above-mentioned regions with raised median tubercles in Hyas ).