Calliocrinus sp.

Ausich, William I., Wilson, Mark A. & Vinn, Olev, 2012, Crinoids from the Silurian of Western Estonia, Acta Palaeontologica Polonica 57 (3), pp. 613-631 : 622

Calliocrinus sp.

Fig. 3G .

Material.—TUG 1395−5 and TUG 1395−6 are examples of this plate with a bifurcating spine from the Ninase Member of the Jaani Formation, Wenlock, Silurian at Suuriku Cliff, Saaremaa, Estonia.

Discussion.—Isolated, long (approximately 25 mm) and wide (approximately 35 mm) bifurcating spine plates ( Fig. 3G ) occur at localities in the Ninase Member of the Jaani Formation. These are assigned herein to the genus Calliocrinus d’Orbigny, 1850 , which is a eucalyptocrinitid in which many species have long, spinose plates. Depending on the species, taxa from the Wenlock and Ludlow of the Isle of Gotland ( Angelin 1878) may have prominent spines from radial plates, first interradial plates, proximal tegmen plates, or as a “parasol” on the distal−most plates of the anal tube. Angelin (1878: pl. 28: 15) only illustrated a single species, C. murchisonianus Angelin, 1878 with bifurcating plates; although broadly similar, the new Estonian material has a much more obtuse angle of spine divergence compared to the Gotland specimen. Thus, the Estonian spine plates are retained in Calliocrinus sp. until more complete specimens become available.

Figures

Fig. 3. Camerate crinoids from the Silurian of Estonia. A, B. Middle Äigu Beds, Kaugatuma Formation (Pridoli), Kaugatuma Cliff. A. Eucalyptocrinites tumidus sp. nov., GIT 405−243. A1, lateral view of crown, note modestly expanding partition plates; A2, basal view of calyx, note nodose calyx plates; A3, tegmen view of crown, note flat tegmen top. B. Calliocrinus sedgwickianus sp. nov., TUG 1395−8. Basal view of a portion of the basal and radial circlets, all circular pits are the trace fossil Oichnus. C. Eucalyptocrinites sp., GIT 405−238, Jaani Formation (Wenlock), Suuriku Cliff. Lateral view of calyx. D. Eucalyptocrinites sp. 2., TUG 1395−13, Ninase Member, Jaani Formation (Wenlock), Panga Cliff. D1, tegmen view of crown; D2, B−ray view of partial crown, note deep elongate groove on well−preserved partition plate. E. Periechocrinus longimanus (Angelin, 1878), GIT 405−4−1, Jaani Formation (Wenlock), Janni Cliff. Lateral view of partial calyx, calyx sutures very indistinct. F. Eucalyptocrinites sp. 1, TUG 1375−3, Jaani Formation (Wenlock), Undva Cliff. Lateral view of broken crown. G. Calliocrinus sp., TUG 1395−6, Ninase Member, Jaani Formation (Wenlock), Suuriku Cliff. Broadly bifurcating spine. H. Eucalyptocrinites sp. 1, TUG 1375−2, Jaani Formation (Wenlock), Undva Cliff. Lateral view of crown of juvenile. Scale bars 10 mm.