- Test ovate in outline tapering to a rounded or truncated point posteriorly. low conical in profile; weak anterior sulcus.
- Apical disc tetrabasal; elongate and disjunct. Ocular plates II and IV meeting behind genital plate 2; genital plates 1 and 4 abutting and immediately posterior to ocular plates II and IV; catenal plates present as thin, generally isolated plates between anterior and posterior parts of apical disc.
- Posterior ambulacra and their ocular plates about midway between anterior part of apical disc and posterior periproct. Posterior oculars not clearly seen and relatively small. Thin isolated catenal plates may be present between posterior oculars and periproct but generally absent.
- All five ambulacra flush adapically, narrow and with small, oblique pore-pairs. Paired ambulacra with plates about twice as wide as tall; relatively dense.
- Ambulacrum III weakly sunken at ambitus and forming a distinct groove adorally.
- Periproct posterior at pointed end of test; subcircular.
- A small number of enlarged pore-pairs adorally with some offsetting of pore-pairs close to the peristome. One oral plate in each zone bearing two pore-pairs.
- Peristome small, circular, downward-facing but slightly inclined towards anterior sulcus.
- Plastron plating not discernable; fully tuberculate and triangular in shape.
- Aboral tuberculation of small scattered tubercles set in a groundmass of granules.
Upper Jurassic (Oxfordian) to Lower Cretaceous (Valanginian), Europe.
Collyrites trigonalis Desor, in Desor & de Loriol, 1872, p. 168 [?=C. carinatus Leske, 1778], by subsequent designation of Savin 1903, p. 50.
- C. trigonalis (Desor, 1872); Tithonian, Switzerland [?=C. carinatus Leske, 1778].
- C. capistrata (Goldfuss, 1829); Oxfordian-Kimmeridgian, Europe.
- C. conica (Cotteau, 1850); Oxfordian, France.
- C. bicordata (Leske, 1778); Oxfordian, western Europe.
- C. saricourensis (Lambert & Thiery, 1908); Oxfordian, France.
- C. oblonga (d'Orbigny, 1853); Valanginian, Europe.
- ?Proacrolusia kelatensis Poretzkaja, 1974; Oxfordian, Kopet Dag
|Classification and/or Status
Irregularia, Stem group Atelostomata, Collyritidae.
Like Collyrites in disc structure, but with only a small number of thin and largely isolated catinal plates between the anterior and posterior parts of the apical disc, rather than a broad and continuous swathe of oblong plates. Ocular plates II and IV typically offset rather than opposite.
Jesionek-Szymanska, W. 1963. Echinides irreguliers du Dogger de Pologne. Actes Palaeontologica Polonica 8(3), 293-396, pls 1-7.