Phasmon, Huang & Ahyong & Shih, 2020

Huang, Chao, Ahyong, Shane T. & Shih, Hsi-Te, 2020, The second known stygomorphic freshwater crab from China, Phasmon typhlops gen. nov. et sp. nov. (Crustacea, Decapoda, Potamidae), diverged at the beginning of the Late Miocene, ZooKeys 1008, pp. 1-15 : 1

publication ID

https://dx.doi.org/10.3897/zookeys.1008.58854

publication LSID

lsid:zoobank.org:pub:6BF494BE-A31B-42D7-88AF-2AB04EEB4725

persistent identifier

https://treatment.plazi.org/id/0BD28B59-9BE1-4679-AD9C-268006C41E77

taxon LSID

lsid:zoobank.org:act:0BD28B59-9BE1-4679-AD9C-268006C41E77

treatment provided by

ZooKeys by Pensoft

scientific name

Phasmon
status

gen. nov.

Phasmon gen. nov. Figs 1 View Figure 1 , 2 View Figure 2 , 3 View Figure 3 , 4 View Figure 4

Type species.

Phasmon typhlops , by present designation.

Diagnosis.

Small sized (carapace width less than 30 mm). Carapace 1.6 × wider than long; fronto-orbital width about twice width of posterior margin; dorsal surface weakly convex (Figs 1 View Figure 1 , 2A View Figure 2 ); frontal margin weakly sinuous, continuous with supraorbital margin, forming almost straight anterior margin of carapace in dorsal view (Fig. 1 View Figure 1 ); postorbital and epigastric cristae almost indiscernible (Figs 1 View Figure 1 , 2A View Figure 2 ); orbit shallow, eyes vestigial, almost immovable, length about half orbital width; cornea reduced, unpigmented, facets absent; external orbital angle very wide, confluent with anterolateral margin (Figs 1 View Figure 1 , 2A View Figure 2 ). Epibranchial tooth inconspicuous. Median lobe of epistome broadly triangular (Fig. 2A View Figure 2 ). Maxilliped 3 ischium length less than twice width; exopod reaching beyond distal edge of ischium, flagellum well-developed (Fig. 3A View Figure 3 ). Cheliped fingers without gape when closed (Fig. 3D, E View Figure 3 ). Male anterior thoracic sternum very wide, around 2.3 times as wide as long (Fig. 2B View Figure 2 ). Male pleon triangular (Fig. 2C View Figure 2 ). G1 tapering anteriorly, tip narrow but blunt (Figs 3C View Figure 3 , 4A, B View Figure 4 ). G2 distal segment tip pointed (Figs 3B View Figure 3 , 4C, D View Figure 4 ). Female vulvae on sternite 6, reaching sutures of sternites 5/6 anteriorly, very widely spaced from one another (Fig. 2F View Figure 2 ).

Etymology.

The genus name is an arbitrary combination of the Latin word “phasma”, meaning ghost, which refers to the type species’ pale appearance and dark habitat, and the genus name Potamon , which is the type genus of the family. Gender neuter.

Kingdom

Animalia

Phylum

Arthropoda

Class

Malacostraca

Order

Decapoda

Family

Potamidae