Hungarocypris suranareeae, Savatenalinton, Sukonthip & Suttajit, Maitree, 2016

Savatenalinton, Sukonthip & Suttajit, Maitree, 2016, A checklist of Recent non-marine ostracods (Crustacea: Ostracoda) from Thailand, including descriptions of two new species, Zootaxa 4067 (1), pp. 1-34 : 28

Hungarocypris

The Hungarocypridinae Bronshtein, 1947 is mainly distinguished from other subfamilies in the Cyprididae by the presence of two posterior setae (defined here as Sp1 and Sp2) on the caudal rami. Based on this taxonomic character, the genus Hungarocypris was established ( Vávra 1906) and composed of two species at that time: Hungarocypris madaraszi (Orley, 1886) and Hungarocypris gawemulleri Vávra, 1906 . Hungarocypris madaraszi , originally placed in Notodromas , was designated as type species of the genus. It was described based on material from Hungary and subsequently reported from other regions in Europe ( Meisch 2000, Danielopol et al. 2008). Hungarocypris gawemulleri was discovered for the first time from the Central part of Thailand ( Vávra 1906), and has not been found since the original description. The occurrence of this species in Sumatra ( Tressler 1937) is not taken into account, as identification is doubtful (see Victor & Fernando 1981a). Subsequently, three other Hungarocypris were discovered: H. asymmetrica Victor & Fernando, 1981 , H. serrata Chen, 1983 and H. levigata Chen, 1991 . The former was recorded from Indonesia while the latter two were Chinese representatives. Hence, H. suranareeae n. sp. described here is the third species of the genus in the Oriental region and the second one in Thailand. To date, this genus comprises six species, and each appears to be endemic to its own region.

The distribution of the genus Hungarocypris was discussed by Victor & Fernando (1981a). They proposed that salinity and temperature of palaeoenvironments were the effective factors resulting in the biogeographical dispersal in the genus. According to the occurrences only in the Palaearctic and Oriental regions, Hungarocypris is an Eurasian endemic genus and seems to contain two lineages. In the Palaearctic lineage, both Recent and fossil material were recorded ( Meisch 2000, Danielopol et al. 2008), while the Oriental lineage includes only the Recent representatives. Thus, the Palaearctic lineage could be older. Based on fossil evidence at the present time, the genus has existed since the Miocene epoch ( Victor & Fernando 1982, Danielopol et al. 2008). Among all six living Hungarocypris , H. madaraszi could be the oldest species as it was reported from the Pleistocene ( Meisch 2000). The Oriental lineage, which comprises three species ( H. asymmetrica , H. gawemulleri and H. suranareeae n. sp.), is so far only known from Southeast Asia. Hungarocypris asymmetrica was described from a rice field near Lake Tempe in Southeast Sulawesi, which is on the Asian tectonic plate. This island is believed to have formed about 60 million years ago. Hungarocypris gawemulleri and H. suranareeae n. sp. were reported from Thailand, which is located on the Indochina Peninsula. This peninsula was formed 220 million years before present. Therefore, it may be interpreted that H. asymmetrica possibly evolved from the Indochinese Hungarocypris ancestor in the period not older than the early Cenozoic era. However, this is as yet unconfirmed by the fossil records in these regions.