The spatangoid genus Schizaster Agassiz is recorded, for the first time, from the Lutetian (Middle Eocene) deposits of Sargaz area, south of Kerman, Iran. The Lutetian sediments of Sargaz region contain a rich and divers echinoid fauna represented by Cidaridae, Conoclypeidae, Echinolampadidae, Toxopneustidae, Phymosomatidae and Schizasteridae. Schizasteroid echinoids are an important component ...

echinoids fauna are common and distributed in the lower miocene deposits of the bagher abad area, northeast isfahan, central iran.there are six echinoid taxa belonging to the echinoidea class that can be described as: clypeaster intermedius, prinocidaris sp. andspines related to: eucidaris zaemays, stylocidaris polyacantha, spatangoid sp. and prinocidaris sp. bivalves, foraminifers,bryozoans, b...

a new species of cassiduloid echinoids, pygaulus baghinensis is reported for the first time from aptian sediments of baghin area, west of kerman, iran. the diagnostic features of the species are centrally positioned of the apical disc and approximately low profile of the test. variation in gonopore size in different individuals allows to conclude that p. baghinensis is sexually dimorphic. speci...

the spatangoid genus schizaster agassiz is recorded, for the first time, from the lutetian (middle eocene) deposits of sargaz area, south of kerman, iran. the lutetian sediments of sargaz region contain a rich and divers echinoid fauna represented by cidaridae, conoclypeidae, echinolampadidae, toxopneustidae, phymosomatidae and schizasteridae. schizasteroid echinoids are an important component ...

abderaz formation is one of the upper cretaceous formations in the kopet-dagh sedimentary basin. a stratigraphic section from the mentioned formation is selected for detailed systematic description with regard to echinoids. numerous well preserved representatives of the families mircrasteridae wright, 1857 and echinocorythidae lambert, 1920 are described from the ghaleh-zoo stratigraphic sectio...

We explore numerically the formation of Turing patterns in a confined circular domain with small aspect ratio. Our results show that stable fivefold patterns are formed over a well defined range of disk sizes, offering a possible mechanism for inducing the fivefold symmetry observed in early development of regular echinoids. Using this pattern as a seed, more complex biological structures can b...

two new species of an arbacioid echinoid, genus goniopygus, are reported for the first time from aptiansediments of baghin area, kerman, iran. the main features of the species lie in apical disc and peristomediameter. in goniopygus triangularis sp. nov., the periperoct is triangular in shape with three small, sunkentubercles, located alternatively adjacent to the periperoct, while goniopygus an...