The Echinoid Directory

• Test discoidal with flat base and thin edges. Much wider than long and slightly indented at posterior ambulacra.
• Apical disc central with four or five gonopores.
• Petals well developed; anterior petal converging distally, others closed; trailing pores beyond end.
• Ambulacral zones much wider than interambulacral zones at ambitus.
• Basicoronal circlet pentastellate with interambulacral plates extremely elongate and projecting.
• Food grooves bifurcating immediately distal to the basicoronal plates without distal branching.
• Periproct opening marginal, between the third and fourth pairs of post-basicoronal interambulacral plates.
• Interambulacra continuous on oral surface.
• Internal partitioning extremely dense and spongiform.

Eocene, the Americas.

Scutella coosensis Kew, 1920, by original designation.

• E.coosensis (Kew, 1920); Middle & Upper Eocene, Oregon, California.
• E. mirandae Parma, 1985; ?Eocene, Santa Cruz, Argentina.
• E. (Tigilella) kamtschatica Shmidt, 1975; Late Eocene, Western Kamchatka
  
• Possibly others unnamed (see Durham 1955, p. 157).

Clypeasteroida, Scutellina, Scutelliformes, Scutellidea, Eoscutellidae.

Presumed monophyletic.

Distinguished from Parascutella and Parmulechinus by the strongly projecting interambulacral plates of the basicoronal circlet and by its relatively wide test. Distinguished from the similar-shaped Amplaster by its lack of anal lunule. Possible stem-group Scutellidea or may be an early member of the Monophorasteridae or Scutasteridae.

Parma, , S. 1985. Eoscutella Grant y Hertlein (Echinodermata: Clypeasteroida) en el Patagoniano (Terciario Inferior) de la Provincia de Santa Cruz, Republica Aregntina. Ameghiniana 22, 35-41.

Mortensen, T. 1948. A Monograph of the Echinoidea IV.2 Clypeasteroida. C. A. Reitzel, Copenhagen.

J. W. Durham 1955. Classification of clypeasteroid echinoids. University of California Publications in Geological Sciences 31(4), 73-198.