Archeoxus, VENTROSUS SMIRNOV, 1992

Kotov, Alexey A., 2009, A revision of the extinct Mesozoic family Prochydoridae Smirnov, 1992 (Crustacea: Cladocera) with a discussion of its phylogenetic position, Zoological Journal of the Linnean Society 155 (2), pp. 253-265 : 257-259

ARCHEOXUS ’ VENTROSUS SMIRNOV, 1992

( FIGS 1F , 3G, H)

Smirnov, 1992a: 113, figs 4G, H, 14A–B Type locality: Khotont, Jurassic–Cretaceous boundary (see above).

Holotype: PIN 4307/2027.

Description: Body elongated, subovoid (height/ length = about 0.6) if not deformed in the holotype. Antennal formula (5)–(1)–(3)/(1)–(1)–(3). Gut not convoluted, especially wide. Length about 2 mm.

Comments: Preservation of specimen PIN 4307/2027 is insufficient for its accurate description. It is provisionally placed in the genus Archeoxus . The species is probably a member of the Prochydoridae , but no diagnostic traits of generic rank except for the elongated body and relatively long antenna II are seen.

Figures

Figure 1. Drawings of Upper Mesozoic Prochydoridae based on SEM photographs. A, Prochydorus rotundus from Khotont, reconstruction based on a series of specimens. B, antenna II of holotype, PIN 4307/2040. C, specimen PIN 4307/2031 from Khotont, antenna II. D, Archeoxus mirabilis from Khotont, reconstruction based on a series of specimens. E, antenna II of specimen PIN 4307/2018. F, ‘Archeoxus’ vetrosus from Khotont, antenna II of holotype PIN 4307/2027. G, Palaeorak scherbakovi gen. nov., sp. nov. from Khasurty, holotype 5026/178. H, reconstruction of general view based on series of specimens. I, postabdominal claw, 5026/177. J, antenna II, 5026/179. Scale bars: 1 mm.