Latereschara d’ Orbigny, 1852

Taylor, Paul D., Martha, Silviu O. & Gordon, Dennis P., 2018, Synopsis of ‘ onychocellid’ cheilostome bryozoan genera, Journal of Natural History (J. Nat. Hist.) 52 (25 - 26), pp. 1657-1721 : 1687-1688

Genus Latereschara d’ Orbigny, 1852

( Figure 17 )

Type species

Eschara achates d’ Orbigny, 1851 , by monotypy. Late Cretaceous, Senonian [?Coniacian], Fécamp, Seine Maritime, Normandy, France .

Diagnosis

Colony erect, bifoliate, palmate ( Figure 17 (a)). Autozooids hexagonal; zooidal boundaries raised. Cryptocyst extensive, depressed, granular. Gymnocyst lacking. Opesia subterminal, occupying about half of frontal surface, circular or longitudinally elliptical ( Figure 17 (b)). Ovicells unknown. Avicularia vicarious, symmetrical, about the same length of an autozooid but slightly narrower, occupying lateral edges of branches ( Figure 17 (c)); opesia longitudinally arch shaped; rostrum triangular, moderately short.

Remarks

The type species of this genus was redescribed by Gordon and Taylor (2005) based on a study of d’ Orbigny’ s type material. Brydone (1930) attributed five species from the English Chalk to Latereschara , none having the distinctive marginal avicularia exhibited by the type species. Material from the Turonian of Bohemia identified by Zágoršek and Vodrážka (2006) as Latereschara achates also lacks the characteristic marginal avicularia and may belong to a different species. Contrary to Voigt (1959, p. 10), there is little justification for assigning Eschara galeata von Hagenow, 1846 to Latereschara as this species also lacks marginal avicularia and has semielliptical rather than rounded opesiae. The elimination of these species leaves Latereschara monospecific for L. achates .

Range

Cretaceous (?Coniacian).

Figures

Figure 17. Latereschara achates d’Orbigny; Late Cretaceous, Senonian [?Coniacian], Fécamp, Normandy, Seine Maritime, France; lectotype, MNHN R61521; (a) palmate branch; (b) autozooids; (c) avicularia along edge of branch. Scale bars: a = 1 mm; b = 200 µm; c = 300 µm.