The Echinoid Directory

 Paleopneustine spatangoids with:

• ovate test with or without anterior sulcus;
• apical disc ethmolytic with 3 or 4 gonopores;
• anterior ambulacrum narrow, without differentiated pore-pairs and funnel-building tube-feet;
• petals straight and gently sunken to almost flush, pore-pairs elongate;
• sternal plates large and tuberculate; episternals biserial and offset; not indented to rear by adjacent ambulacral plates;
• marginal and peripetalous fasciole combined anteriorly; the combined band passing several plates below the ends of the anterior petals and inframarginally over plate 3 in interambulacra 2 and 3. Posterior part of marginal fasciole may or may not be present in adult;
• aboral tuberculation heterogeneous.

Upper Cretaceous (Campanian-Maastrichtian) to Recent; Europe, North America, Africa, Asia, Antarctica.

This family was originally established by Lambert (1905) for forms with a peripetalous fasciole band that descends very low around the anterior. Compared to Schizasteridae the marginal and peripetalous bands divide on the fourth interambulacral plate in columns 1.b and 4.a, not the fifth, and the anterior band passes several plates beneath the ends of the petals rather than bounding their distal ends. Around the anterior the fasciole passes over plate 3 in the interambulacra 2 and 3, not plates 4 or 5.

Cooke (1959) erected the family Unifasciidae to include only Unifascia a taxon that lacks the posterior part of its marginal fasciole. However, like Prenasteridae, this fasciole band crosses plate 4.a.4 and 1.b.4, passes several plates beneath the petals and descends subambitally around the anterior. It thus has an identical fasciole path as Prenaster and simply has lost the posterior portion of the marginal fasicole.

The following taxon may belong here but is too poorly known at present to place with any degree of certainty:
Antiqubrissus

Cooke, C. W. 1959. Cenozoic echinoids of Eastern United States. United States Geological Survey Professional Paper 321, 1-103, pls 1-43.