TERRESTRICYPRIDINI ( SHORNIKOV, 1980 )

Pinto, R. L., Rocha, C. E. F. & Martens, K., 2005, On new terrestrial ostracods (Crustacea, Ostracoda) from Brazil, primarily from São Paulo State, Zoological Journal of the Linnean Society 145 (2), pp. 145-173 : 156

TRIBE TERRESTRICYPRIDINI ( SHORNIKOV, 1980)

(CHANGE OF RANK)

Diagnosis

Small (L = 0.3–0.4 mm) candonids, with reniform valves in lateral view and narrow carapace with straight margins in dorsal view. All limbs with some aspect of reduced chaetotaxy (fusion of segments, loss of setae) to varying degrees in the different genera. A1 with 5 segments, with various segments fused in the different genera; endopodal segments 1 and 2 + 3 in T3 devoid of setae.

Remarks

1. Shornikov (1980) created the new family Terrestricyprididae to accommodate Terrestricypris . However, this genus clearly belongs in the Candonidae , a group where reduction in chaetotaxy (i.e. number of segments, number of setae and claws) is not uncommon (see Danielopol, 1978; Karanovic & Marmonier, 2003; I. Karanovic unpubl. data). This taxon is here retained, albeit with a change of rank, namely as a tribe within the Candoninae .

2. Terrestricypridini at present comprises 3 genera, Terrestricandona , Terrestricypris and Caaporacandona gen. nov., which together form a clear evolutionary lineage (see Discussion). It is possible that more genera will be found that will represent either more or less derived stages of evolution within this lineages. In the latter case, the diagnosis of the tribe might require modification.

3. Karanovic, in a series of papers (2003a, b and several papers in press), has described an impressive number of species and genera of subterranean Candoninae from Western Australia. These ostracods also display loss of chaetotaxy in, amongst other limbs, the A1. However, the Australian interstitial taxa mostly also have a reduction in the chaetotaxy of the CR, which is well developed in all Terrestricypridini , and have very different valves. It is thus accepted here that the South American terrestrial and Autralian interstitial candonids belong to different lineages.

4. Species of all three genera of Terrestricypridini have a distinct juvenile aspect (small size, narrow calcified inner lamella, reduced number of muscle scars). It is therefore probable that the presence of these genera in the fossil record has consistently been overlooked.