Eocarcinus

Eocarcinus
Temporal range: Pliensbachian
Eocarcinus fossil.jpg
Holotype (top) and paratype (bottom) specimens
Scientific classification
Kingdom:
Phylum:
Subphylum:
Class:
Order:
Infraorder:
Family:
Eocarcinidae

Withers, 1932
Genus:
Eocarcinus

Withers, 1932
Species:
E. praecursor
Binomial name
Eocarcinus praecursor
Withers, 1932
Reconstruction based on 2020 reanalysis
Additional paratype specimen

Eocarcinus praecursor is a Jurassic species of decapod crustacean, sufficiently distinct from its relatives to be placed in its own family (Eocarcinidae). Often considered the oldest true crab, it was considered by a 2010 study to be an early member of the Anomura. However, a reanalysis in 2020 again found it to be the earliest known stem-group crab.

Distribution

It lived during the early Pliensbachian age (Lower Jurassic), and has been found in rocks at two sites in the United Kingdom – Mickelton Tunnel (near Aston Magna), Gloucestershire and Runswick Bay, Yorkshire.

Description

In many of its characters, it represents a transitional stage between the Glypheoidea and the Middle Jurassic crabs in the Prosopidae. Since its ancestors were long-tailed decapods, and its successors were short-tailed crabs, Eocarcinus has been described as "the lobster who decided to become a crab". Previously considered to be the oldest known true crab, a 2010 revision concluded that Eocarcinus could not be accommodated among the Brachyura, and was instead transferred to the Anomura. However, a 2020 renalysis found that it was again the earliest known stem-group crab, but that it had not undergone the process of carcinisation.


This page was last updated at 2023-01-17 08:50 UTC. Update now. View original page.

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