Myodocopid Ostracoda from the late Permian of Greece and a basic classification for Paleozoic and Mesozoic Myodocopida

Abstract

Komicker, Louis S., and I.G. Sohn. Myodocopid Ostracoda from the Late Permian of Greece and a Basic Classification for Paleozoic and Mesozoic Myodocopida. Smithsonian Contribu¬ tions to Paleobiology, number 91, 33 pages, 22 figures, 2000.-Four new genera and six new species are described from the top of the Episkopi Formation (Dorashamian) on the island of Hydra, Greece: Cypridinelliforma rex (new species), Nodophilomedes phoenix (new genus, new species), Swainella bex (new genus, new species), Triadocypris pax (new species), Siveterella pax (new genus, new species), Siveterella flex (new species), and Sylvesterella (new genus), based on specimens in the collection from Greece. Supplementary descriptions are pre¬ sented of Philomedes rankiniana (Jones and Kirkby, 1867) and Eocypridina radiata (Jones and Kirkby, 1874). A basic classification proposed for Paleozoic and Mesozoic Myodocopida includes a new suborder, three new superfamilies, and three new families. OFFICIAL publication DATE is handstamped in a limited number of initial copies and is recorded in the Institution's annual report, Annals of the Smithsonian Institution. SERIES COVER DESIGN: The trilobite Phacops rana Green.

An exceptionally preserved myodocopid ostracod from the Silurian of Herefordshire, UK

“…figure 1a,l ). The subcircular lateral outline combined with a long, tapered rostrum and associated well-developed rostral incisure, together with the presence of a well-developed caudal siphon, recall other myodocopid families, especially cypridinids (supposed Silurian to Recent) and others such as bolbozoids and entomochonchids, which are known only from the Palaeozoic (Siveter & Vannier 1990;Kornicker & Sohn 2000). In limb morphology, subcircular lateral valve outline and the presence of a caudal siphon, N. flata is also like the Sarsiellidae (no known fossil representatives), but such a prominent rostrum and especially a deep rostral incisure are not typical of that family.…”

A Silurian myodocope with preserved soft-parts: cautioning the interpretation of the shell-based ostracod record

“…more acute posterior wing-like structures) and valve ornament may represent ontogenetic variation. At around 1 cm long, the larger specimen is comparable in size to adults of many Recent and fossil myodocopid species, which range up to about 30 mm in length [5,9,34].…”

“…Supposed myodocopids recorded from the fossil record number many tens of species, of which some 20 have been assigned to the Cylindroleberididae; however, only six, including five cylindroleberidids, are confirmed as myodocopids based on preserved soft-parts ( [9,10] and references herein). Of the six species, the carapace morphology of the two post-Palaeozoic forms, the cylindroleberidids Triadocypris spitzbergensis Weitschat ([35] Triassic) and Juraleberis jubata Vannier & Siveter ([36] Jurassic), accords with that of Recent myodocopids.…”

“…Pelagic forms, exclusively members of the Myodocopa, one of the two major living ostracod groups, arose via an ecological shift in the Silurian [6,7]. Myodocopes typically have weakly calcified valves and, consequently, a scant fossil record [8][9][10][11], which begins in the Late Ordovician [12]. The soft-parts of ostracods are rarely fossilized [13,14].…”

The oldest record of gnathostome fossils from Greece: Chondrichthyes from the Lopingian of Hydra Island

“…The late Paleozoic outcrops, first reported by Renz (1910), are located along the southeastern coast of the island and comprise shallow water carbonate and siliciclastic successions (Figure 1.2-3), which were deposited on the northwestern Paleotethyan margin, forming the base of the "sub-Pelagonian" zone (Baud et al, 1990;Grant et al, 1991). A diverse array of fossils is known from the autochthonous Permian sedimentary successions of Hydra, including algae (Jenny et al, 2004), benthic foraminifera (Vachard et al, 1995;Jenny et al, 2004;Vachard et al, 2008), ostracods (Crasquin-Soleau and Baud, 1998;Kornicker and Sohn, 2000) and brachiopods (Grant, 1972(Grant, , 1995Shen and Clapham, 2009). Conodonts are mostly known from the upper part of the Lopingian limestone (Nestell and Wardlaw, 1987), where the successive occurrences of Neogondolella leveni and Neogondolella orientalis indicate a Wuchiapingian (early Lopingian) age (Kozur, 1975).…”