Echinoidea taxon details
original description
Jagt, J. W. M., Jagt-Yazykova, E. A. & Zonova, T. D. 2013. Notes on selected Cretaceous echinoids from south-central Sakhalin, Far East Russia. Netherlands Journal of Geosciences / Geologie en Mijnbouw 92/2-3, 123-132.
page(s): 127-130; figs 6A-F, 7A-C [details] Available for editors
Holotype NHMM 2012 077, geounit Sakhalin [details]
From editor or global species database
Diagnosis Medium-sized hemiasterid, of subangular outline, near-equal in length and width, maximum test width just posterior of apical disc, with very shallow frontal notch and sloping posterior face, interambulacrum 5 lacking median keel; apical disc subcentral, semi-ethmophract with four gonopores, genital plate 2 just separating posterior genital plates; ambulacrum III narrow and slightly sunken, shallowing towards ambitus; paired ambulacra relatively long, petaloid, moderately sunken and weakly bowed; anterior and posterior petals near equal in length; pore pairs elongate and slit like; peristome small, pentagonal and facing downwards, peristomial area deeply sunken with interambulacra 2 and 3 forming conspicuous bulges; sternal plates asymmetrical, median suture oblique; periproct ovate, situated near top of sloping posterior face; incomplete peripetalous fasciole (parafasciole), indented behind anterior petals; aboral tuberculation of widely spaced small tubercles surrounded by miliaries. [details]
Etymology In commemoration of Natalya Dmitrievna Zonova (1940-2007), mother of the second and younger sister of the third author. [details]
Fossil range Lowermost Campanian, Menuites (Neopachydiscus) naumanni Zone [details]
Stratigraphy Bykov Formation, Member 10 [details]
Type locality Locality 134-6, River Naiba, at the confluence with its right tributary, the Nagornaya, southern Sakhalin
[details]
From editor or global species database
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