The Echinoid Directory

Abertella Durham, 1953, p. 350

[= Karlaster Marchesini Santos, 1958, p. 16, type species Karlaster pirabensis Marchesini Santos, 1958. ]

Diagnostic Features
  • Test very thin with flat base and sharp margin.
  • Internal supports comprising adradial bars and stellate clusters.
  • Apical disc cnetral with four gonopores.
  • Broad, open anal notch.
  • Interambulacral columns all disjunct adorally, separated by the first post-basicoronal pair of ambulacral plates.
  • Periproct submarginal; opening bounded by second pair of post-basicoronal interambulacral plates.
  • Food grooves bifurcate at edge of basicoronal plate; fine distal branches well developed
  • Ambulacra wider than interambulacra at ambitus.
Distribution
Upper Oligocene to Miocene, southern USA, Mexico, Guatemala, Cuba, Brazil and Argentina.
Name gender feminine
Type
Scutella aberti Conrad, 1842, p. 194, by original designation.
Species Included
  • A. aberti (Conrad, 1842); Middle Miocene, southern USA.
  • A. cazonensis Kew, 1917; Upper Oligocene to Lower Miocene, California, USA
  • A. dengleri Osborne & Ciampaglio, 2010; Upper Miocene, southern USA.
  • A. gualichensis Martínez, Reichler & Mooi, 2005; Early-Middle Miocene, Argentina.
  • A. kewi Durham, 1957; Middle Miocene, Mexico.
  • A. miskellyi Kroh et al. 2013; Miocene, Argentina
  • A. palmeri Durham 1957; ?Early Miocene, Guatemala.
  • A. pirabensis (Marchesini Santos, 1958); Lower Miocene, Brazil. [= A. complanata Brito, 1981]
  • ? A. cazonensis (Kew in Dickerson & Kew, 1917), Miocene, Mexico.
  • ? A. habanensis (Sanchez Roig, 1949), ?Miocene, Cuba.
Classification and/or Status

Clypeasteroida; Scutellina; Scutelliformes; Scutellidea, Abertellidae.

Monophyletic

Remarks

Distinguished from other scutellines by its rather open posterior notch and by having all five interambulacral columns disjunct on the oral surface. Probably sister-group to Mellitidae plus Astriclypeidae as it shares with them a well-developed spongy internal calcification around the margins.

See Kroh et al. (2013) for a detailed discussion of this genus and its species.

Durham, J. W. (1955) Classification of clypeasteroid echinoids. California University Publications in Geological Sciences 31, 73-198.

Kroh, A., Mooi, R., Del Rio, C. & Neumann, C. 2013. A new late Cenozoic species of Abertwlla (Echinoidea: Clypeasteroida) from Patagonia. Zootaxa 3608 (5), 369-378.