DOI: 10.5281/zenodo.15143178
title: Table 1 in A new species of Peribrissus (Echinoidea, Spatangoida) from the middle Miocene of South Australia

description: Table 1. Comparison of diagnostic features of Peribrissus janiceae sp. nov. with those of the type species of the genus, P. saheliensis Pomel, 1883, and P. sotgiai Giorgio, 1923.
Diagnostic featurePeribrissus janiceae sp. nov.Peribrissus saheliensis PomelPeribrissus sotgiai GiorgioWidth/length ratio of test89.7%TLSimilarSimilarMaximum width locationMarginally posterior atMarginally anterior, approx.Similar to P. saheliensis54.3%TL45%TLHeight//length ratio of test66.4%TLNot knownApprox. 54%TLMaximum height locationSlightly anterior at 44.8%Well anterior but posterior ofWell posterior, approx.apical disk, approx. 30%TL68%TLAnterior lateral profileHigh, vertically convexSlopes forward from apex atSimilar to P. janiceaeapprox. 35°Posterior lateral profileHigh vertical truncationOblique truncationOblique truncationAdoral surface lateral profileFlat, posterior of peristomeUnknown (type specimenSlightly swollen posterior ofcompressed)centreSulcusMax. depth/width ratio approx.Figured much deeper with aFigured far shallower and1:4.6, occurs below ambitusdepth/width ratio of approx. 1:2.2wider than P. janiceaeApical system location and type21%TL, ethmolitic, 3Approx. 33%TL, detail of apicalApprox. average of 2gonopores (none in plate G2)system unknown (Pomel 1887).specimens 25%TL,Stefenini (1911) incorrectlyethmolitic. Giorgio’sassumes 4 gonopores. Thisdescription refers to 4repeated by Mortensen (1950)gonopores but states the poreand Fisher (1966).in G2 almost atrophiedAmbulacrum III, marginalNot unduly prominent, situatedSimilar to P. janiceaeLarger, far more prominenttuberclesjust outside adradial sutureswith rows further apartDetail of petalsStraight, parallel sided andSimilar, but probably shallowerSimilarsunkenLength differentiation pairedAnterior petals 138% longerSimilar to P. janiceaeMore equal, but posteriorpetalsthan posterior onespetals still shorter thananterior onesAnterior paired petals175°Approx.135°Described as 140°. Giorgio’sdivergence anglefigures, however, suggestdivergence widerPosterior paired petals315°Approx. 295°Similar to P. janiceaedivergence anglePeristomeReniform and slightly sunkenInsufficient information forInsufficient information forcomparisoncomparisonPeriproctVertically elliptical at top ofSemicircular, assumed high onElliptical (axis not clear),posterior truncationposterior truncationhigh on posterior truncationFascioles, marginal andMarginal fasciole occurs justSimilar, but with semipetalousInsufficient information forsemipetalousabove sloping ambitus and isfasciole shown angled forward atcomparison, as stated to bejoined by semipetalous fasciolejunction with marginal fasciole,only visible in some placesat right angles behind andapparently due to less obliquebelow anterior paired petalsdivergence of anterior petals
description: Published as part of Holmes, Francis C., 2011, A new species of Peribrissus (Echinoidea, Spatangoida) from the middle Miocene of South Australia, pp. 33 in Memoirs of Museum Victoria 68 on page 33, DOI: 10.24199/j.mmv.2011.68.02, http://zenodo.org/record/8065078