Cheiragonidae
Encyclopedia
Cheiragonidae is a small family
of crab
s, sometimes called helmet crabs, placed in its own superfamily
, Cheriagonoidea. It comprises three extant species, Erimacrus isenbeckii
, Telmessus acutidens and Telmessus cheiragonus, and 13 extinct species in the three genera Karasawaia, Montezumella and Stintonius. Many of these crabs were formerly treated as members of the Atelecyclidae
. The family's fossil record extends back at least as far as the Eocene
.
Family (biology)
In biological classification, family is* a taxonomic rank. Other well-known ranks are life, domain, kingdom, phylum, class, order, genus, and species, with family fitting between order and genus. As for the other well-known ranks, there is the option of an immediately lower rank, indicated by the...
of crab
Crab
True crabs are decapod crustaceans of the infraorder Brachyura, which typically have a very short projecting "tail" , or where the reduced abdomen is entirely hidden under the thorax...
s, sometimes called helmet crabs, placed in its own superfamily
Taxonomic rank
In biological classification, rank is the level in a taxonomic hierarchy. Examples of taxonomic ranks are species, genus, family, and class. Each rank subsumes under it a number of less general categories...
, Cheriagonoidea. It comprises three extant species, Erimacrus isenbeckii
Horsehair crab
The horsehair crab, Erimacrus isenbeckii, , is a species of crab which is found in the Sea of Okhotsk and the Pacific Ocean and is frequently used in Japanese cuisine.-References:*...
, Telmessus acutidens and Telmessus cheiragonus, and 13 extinct species in the three genera Karasawaia, Montezumella and Stintonius. Many of these crabs were formerly treated as members of the Atelecyclidae
Atelecyclidae
Atelecyclidae is a family of crabs belonging to the Cancroidea superfamily, and currently containing eight genera two of which are extinct. However, the genera other than Atelecyclus do not belong in the Cancroidea, and are to be removed from the family....
. The family's fossil record extends back at least as far as the Eocene
Eocene
The Eocene Epoch, lasting from about 56 to 34 million years ago , is a major division of the geologic timescale and the second epoch of the Paleogene Period in the Cenozoic Era. The Eocene spans the time from the end of the Palaeocene Epoch to the beginning of the Oligocene Epoch. The start of the...
.