Pourtalesia (ontogeny of oral plating)
Description Development of the oral plate pattern during ontogeny: a. The labral plate (1 in green interambulacral area) is in contact with the sternal plate (2). The pairs of ambulacral plates (l - 3 in yellow area) are positioned one beside the other in each column. b. The labral plate (1) is separated from the sternum (2) by one ambulacral plate of column A I and resp. A V (lb2 + ya2). c. The second ambulacral plates 2 in column A I resp. AY (la2 + Vb2) have shifted to the median axis pushing the labral plate (l) anteriorly. d. The ambulacral plates I in column A I resp. A V have pushed the labral plate into the peristomial groove, separating also the plates 1 and 2 in the anterior interambulacra lA 1 and lA 4 (11 from 1ab2 resp. 41 from 4ab2). d. ln ambulacrum I as well as in ambulacrum V the plates 2have shifted to a position the one in front of the other along the axis. After David (1987).
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added on 2009-02-23106 viewsWoRMS taxaScan of drawing Pourtalesia A. Agassiz, 1869checked Kroh, Andreas 2021-02-24From reference Schultz, H. (2009). Sea urchins II: Worldwide irregular d...
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© 2009 Schultz, Heinke