Repository and institutional abbreviation

All figured specimens and important non-figured specimens have a museum number and are deposited in the following institution: Museo de Ciencias Naturales de la Universidad de Zaragoza, Zaragoza, Spain, under the acronyms MPZ2024/97–204. There is also extra cyrtocrinid material that remains in the same collection.

Classification and terminology

The classification and most of the terminology used in descriptions (Fig. 3) follow Hess and Messing (Reference Hess and Messing2011).

Figure 3. Schematic cup of a cyrtocrinid of Eugeniacrinitidae Roemer, Reference Roemer and Bronn1855, typical morphology (1) in aboral view and (2) in lateral view, describing the terminology used here.

Type species

Encrinites cariophilites von Schlotheim, Reference von Schlotheim1813.

Diagnosis

Cup conical to funnel-shaped, rarely nearly cylindrical. Radial articular facets steep and wide in adults, with small aboral ligament fossa and deeply excavated adoral muscle fossae, separated from radial cavity by narrow ledges extending from interradial processes to median notch; interarticular ligaments indistinct. Articular facets separated by small interradial projections. Radial cavity wide and rather shallow. Aboral side of cup entirely occupied by almost flat, articular facet for column. First primibrachials very low. Axillary second primibrachials large, with compact, spearhead-shaped, median prolongation above small, lateral, articular facets for secundibrachials, and joined aborally by symplectial facets as protective covers over adoral side of cup when retracted. Arms small, may be coiled between second primibrachials. Columnals cylindrical to slightly conical, commonly high. Uppermost columnal with diameter equal to base of cup, commonly closely attached to cup. Articular facet of columnals with marginal granulation (after Hess and Messing, Reference Hess and Messing2011; Hess, Reference Hess2014b).

Eugeniacrinites cariophilites (von Schlotheim, Reference von Schlotheim1813) Figure 4

Figure 4. Eugeniacrinites cariophilites (von Schlotheim, Reference von Schlotheim1813) from the middle Oxfordian of Tosos (Zaragoza, Spain), Yátova Formation, layer TO3/27. (1–3) Cup with first columnal still attached in adoral, lateral, and aboral views (MPZ2024/104); (4–7) cup with adoral groove crenulated in adoral, oblique, lateral, and aboral views (MPZ2024/97); (8–11) cup with very distinct interradial processes in adoral, oblique, lateral, and aboral views (MPZ2024/100); (12–15) cup with small interradial processes in adoral, oblique, lateral, and aboral views (MPZ2024/98); (16, 17) second primibrachial in adoral and lateral views (MPZ2024/102); (18, 19) columnal with serpulids in lateral and articular views (MPZ2024/101). All specimens photographed whitened with ammonium chloride sublimated; all scale bars = 1 mm.

Reference Klikushin1996

Eugeniacrinites cariophilites; Klikushin, p. 103, pl. 1, figs. 3–22 (with previous synonymy).

Reference Kaufmann1998

Eugeniacrinites cariophilites; Kaufmann, p. 10, text-fig. 7.5?.

Reference Hess, Salamon and Gorzelak2011

Eugeniacrinites cariophilites; Hess and Messing, p. T181, text-fig. 88.1.

Reference Hess2014b

Eugeniacrinites cariophilites; Hess, p. 123, figs. 2–14.

?Reference Zamora, Aurell, Veitch, Saulsbury, López-Horgue, Ferratges, Arz and Baumiller2018

Eugeniacrinites cariophilites; Zamora et al., p. 788, text-fig. 9a.

Reference Krajewski, Ferré and Salamon2020

Eugeniacrinites cariophilites; Krajewski et al., p. 70, text-fig. 5e, f.

Holotype

Cup figured by Knorr (Reference Knorr1775, pl. 36, fig. 20) and refigured by von Schlotheim, Reference von Schlotheim1813, from the Jurassic of Switzerland (according to Rasmussen, Reference Rasmussen1961, p. 223).

Emended diagnosis

Cup smooth, funnel-shaped, slightly conical or bowl-shaped; pentagonal in adoral view. Radial articular facet steep, large, and almost flat, muscle fossae deep, wide, and oval in adult, more rounded in juveniles. Interradial processes not very high, with a triangular apex, sometimes with a rounded angle. Aboral part of the cup circular or subcircular, flat or slightly concave, with marginal and irregular roughness made up of tubercles that are sometimes elongated and can be folded up. Columnals cylindrical, sometimes with concave sides, crenularium with the same roughness pattern as the aboral part of the cup.

Occurrence

Late Jurassic (Oxfordian) of Spain, Oxfordian and Kimmeridgian of France, Switzerland, Germany, and Early Cretaceous of France? (Rasmussen, Reference Rasmussen1961).

Description

Cups of varying sizes and shapes, slightly higher than wide, funnel-shaped, with a cylindrical aboral part (Fig. 4.2, 4.6). Other cups are wider than high, bowl-shaped (Fig. 4.14). Slight asymmetry sometimes visible. Cups smooth, sutures of radial plates visible, sometimes forming slight grooves in small cups. Clearly pentagonal in adoral view, radial cavity varies in width, moderately deep, adoral groove well marked, fairly deep, interradial grooves more or less distinct, sometimes with crenulated edges (Fig. 4.4, 4.5). Interradial processes of variable height and width, triangular or slightly angular apex (Fig. 4.6, 4.10, 4.14).

Radial articular facet not outward sloping, aboral articular facets slightly crescent-shaped to almost flat, aboral ligament pit small and shallowly depressed, axial canal round, very small, slightly more depressed. Adoral articular facets not very high, wide, sunken, muscular fossae deep, wide, oval (Fig. 4.6) to subrectangular (Fig. 4.14), separated by a deep adoral groove, varying in width. Aboral face circular, sometimes subcircular (Fig. 4.11), facet for the column slightly depressed, contour ornamented with irregular ridges in the crenularium, well-developed areola, central canal small and round. Columnals of variable size, generally short, cylindrical (Fig. 4.2) or with concave sides (Fig. 4.18). Articular facets circular or oval, areola developed, crenularium ornamented with irregular tubercles more or less elongated and branched, lumen small and rounded (Fig. 4.19). Axillary second primibrachial spearhead-shaped (Fig. 4.16), basal part forming an almost right angle with the distal part, articular facet for the secundibrachials small and laterally arranged (Fig. 4.17).

Remarks

The funnel or bowl shape of the cups and the wide adoral articular facets and muscular fossae in adults (Fig. 4.1–4.14) are characteristic of the species Eugeniacrinites cariophilites (Hess, Reference Hess2014b). Variation of the shape of the cups has already been demonstrated by various authors (Quenstedt, Reference Quenstedt1876; Hess, Reference Hess2014b). Some small cups have slightly rounder and narrower muscular fossae, but this is a juvenile feature of the species because the muscular fossae follow the widening of the facets with growth (Fig. 4.6, 4.10, 4.14) (Hess, Reference Hess2014b). The same applies to the interradial fossae, which are more or less distinct depending on the stage of development (Fig. 4.6, 4.10) (Hess, Reference Hess2014b). The Tosos specimens are also variable in the shape of the interradial processes, which can be wider and higher.

The studied material differs from the morphologically related species Lonchocrinus dumortieri (de Loriol, Reference de Loriol1882) in their interradial processes, which are generally still less high, less acuminated, and more curved inwards (Fig. 4.5, 4.9) (de Loriol, Reference de Loriol1882–1884; Hess and Messing, Reference Hess and Messing2011). In addition, L. dumortieri has more vertical and round muscular fossae than E. cariophilites, as well as outwardly sloping radial facets (de Loriol, Reference de Loriol1882–1884). Eugeniacrinites cariophilites can be distinguished from E. crenulatus d'Orbigny, Reference d'Orbigny1850, another Oxfordian species, by its facet to the column, which does not show the same ornamentation (de Loriol, Reference de Loriol1882–1884). In fact, E. cariophilites columnals are cylindrical, with a fine lumen on the articular surface, and a broad areola surrounded by a marginal, irregular crenularium.

Type species

Eugeniacrinites compressus (Goldfuss, Reference Goldfuss1829).

Diagnosis

Cup low, compact, more or less oblique, with granular surface, radial cavity rather small. Facet to column wide, deep, and concave (after Hess and Messing, Reference Hess and Messing2011).

Remarks

The genus name Sclerocrinus Jaekel, Reference Jaekel1891, has no prevalence over Gammarocrinites (Hess, Reference Hess2004; ICZN, 2006), so Gammarocrinites is used here. These two genera differ in shape. The calyx is more massive in Sclerocrinus than in Gammarocrinites and the radial articular facets are rounded in Sclerocrinus (Hess and Messing, Reference Hess and Messing2011) and rather flat in Gammarocrinites. The specimens studied here are low forms, with rather flat articular facets, thus suggesting inclusion in Gammarocrinites.

Lectotype

Cup from the Jura limestone of Germany, Jurassic (Goldfuss, Reference Goldfuss1829, p. 164, pl. L, fig. 5; according to Rasmussen, Reference Rasmussen1961, p. 218).

Emended diagnosis

Cup rather low, wider than high, granulated, asymmetric. Adoral articular facet almost flat, muscle fossae rounded. Sides of radial plates in lateral view straight, slightly concave, or flared at base, with distinctive suture, very finely and geometrically sinuous. Aboral cavity large, delimited by fine edges.

Occurrence

Late Jurassic, Oxfordian from Spain, Oxfordian to Tithonian in Europe (Hess and Messing, Reference Hess and Messing2011).

Description

Cup low, very or slightly asymmetrical, wider than high, pentagonal with rounded edges in adoral view. Highly variable aboral part, ranging from cylindrical (Fig. 5.4) to very flared, sometimes forming slight lobes (Fig. 5.17). Radial cavity highly variable in size, from small (Fig. 5.12) to moderate (Fig. 5.15, 5.18), funnel-shaped form, smooth cavity wall, interradial grooves more or less visible. Interradial processes of variable height, forming small spikes. Radial plate sutures clearly visible, with alternating rectangular lobes and hollows (zygosynostosis) at each end of the plate, becoming entangled at the sutures (Fig. 5.3, 5.5, 5.10, 5.16, 5.19). Marked, rather regular granulation on the cup surface, with small circular granules becoming larger and elongated aborally (Fig. 5.3), sometimes granulation is only visible on the lower contour of the aboral articular facet or totally faded and absent.

Radial articular facets generally slightly sloping outwards, adoral facets fairly flat and shallowly depressed, with variable size and inclination, trapezoidal in lateral view, circular or subcircular muscle fossae. Distinct transverse ridge, sometimes protruding when unabraded. Aboral articular facet of variable size, sometimes higher than the adoral articular facet, sometimes lower, generally as wide as the base of the adoral facets, rounded. Axial canal circular, sometimes subcircular, fairly large, sunken, located above the transverse ridge. Aboral ligament pit large, oval, and deep. Aboral face subcircular (Fig. 5.4), sometimes more pentagonal (Fig. 5.11), moderately deep, large, and conical, with quite distinct suture and sometimes with the outer edges granulated. Facet to the column shows a small, more pronounced depression at the bottom of the cavity and sometimes shows a slight crenularium with irregular granulation (Fig. 5.14, 5.17).

Remarks

Specimens are included within the species Gammarocrinites compressus because of the very distinct granulation around the entire circumference of the section (Fig. 5.3, 5.19) or around the aboral facets, the flat adoral articular facet (Fig. 5.3, 5.10, 5.13, 5.19), the small radial cavity, whose diameter does not appear to exceed the radius of the total section, and the protruding transverse ridge (as described in Goldfuss, Reference Goldfuss1826–1833; Rasmussen, Reference Rasmussen1961; Hess and Messing, Reference Hess and Messing2011). Given the large number of well-preserved samples we studied, we assume that G. compressus and Cyrtocrinus nutans (Goldfuss, Reference Goldfuss1829) have very similar cups, as already discussed in literature (de Loriol, Reference de Loriol1882–1884; Hess and Messing, Reference Hess and Messing2011; Hess, Reference Hess2012). Indeed, granulation is sometimes absent (Fig. 5.7, 5.8), although it remains present on the majority of specimens.

As described by de Loriol (Reference de Loriol1882–1884), it seems that the diameter of the radial cavity is an important feature in the variation of several morphological characters in the adoral part, such as the size of the interradial processes, or the orientation of the adoral articular facet. However, by observing calyxes from other Spanish levels, or by looking at photographs of Cyrtocrinus nutans cups made available to us by the Museum national d'Histoire naturelle de Paris (lot MNHN.F.A08034, collection d'Orbigny 3865), certain differences become apparent in the aboral part or in the shape of the radial plates, thus separation of two species is justifiable. Indeed, in the G. compressus specimens presented here, the aboral cavity appears large and flared, possibly shallow, and surrounded by thin radial plates (Fig. 5.4), sometimes to the point of making the delineation of the aboral cavity indistinct (Fig. 5.11). In C. nutans, this cavity is deep, always well delimited by thick radial plates, making it narrower and more circular. Also, in G. compressus, in lateral view, the radial plates are straight (Fig. 5.3, 5.10), slightly concave, or convex at the base of the sides, showing the maximum width of these plates, most often in the aboral part (sometimes becoming small lobes, as in Fig 5.16) or close to mid-height. Conversely, in C. nutans, the radial plates have strongly convex sides in lateral view, reaching their maximum width just below the aboral radial articular facet, the minimum width being at the base of the calyx.

The species studied here is easily distinguished from the Tithonian species Ascidicrinus pentagonus (Jaekel, Reference Jaekel1891) by its discoidal base without distinct interradial lobes. Material described here is distinguished from many other species by the particular simplexy suture of its radial plates (Fig. 5.3) In literature, only some specimens of the species Cyrtocrinus praenutans Hess, Reference Hess2012, appear to have similar sutures, but are still different in that they are composed of non-rectangular lobes and hollows (Hess, Reference Hess2012). Finally, G. compressus appears to be the only species of the genus Gammarocrinites described from the Oxfordian of Europe.

Type species

Eugeniacrinus moussoni Desor, Reference Desor1845.

Diagnosis

As for the species by monotypy.

Holotype

Rasmussen (Reference Rasmussen1961) referred to P. moussoni as the type species of the genus Pilocrinus, but indicated that no holotype had been designated for P. moussoni.

Diagnosis

Wide, cylindrical or conical cup, with a more or less pronounced mid-height restriction, differentiating a cylindrical adoral part in lateral view and circular in adoral view, from an aboral part forming a more or less flared cap, with a pentagonal or subcircular shape in aboral view. Radial cavity deep and narrow surrounded by well-developed interradial processes. Articular facets are wide and slightly inclined outwards, adoral facet as a sub-horizontal base. Aboral part of cup has a very deep, concave cavity, with a rather wide articular facet for column. Cylindrical to strongly convex columnals. Primibrachials 1 and 2 united by synostosis. Primibrachial 2 axillary with thickened sides, mostly united adorally and enclosing radial furrow. Secundibrachials commonly prolonged on one side but may also be united adorally (modified after Hess and Messing, Reference Hess and Messing2011).

Occurrence

Late Jurassic (Oxfordian) from Spain. Middle Jurassic (Callovian) from Poland (Salamon, Reference Salamon2008) to Late Cretaceous (Campanian) from Europe (Rasmussen, Reference Rasmussen1975).

Description

Cup high, aboral part considerably wider (Fig. 6.7) to slightly wider (Fig. 6.2) than adoral part, constriction at mid-height of varying degree. Smooth cup surface, plate sutures slightly developed, sometimes finely sinuous (Fig. 6.5). Adoral part of cup rounded, aboral part with subcircular or pentagonal outline. Radial cavity deep, moderately wide, adoral grooves deep and distinct, interradial grooves mostly indistinguishable. Thick interradial processes, rather high. Radial articular facets sloping outwards, aboral facet small, more rounded than crescent-shaped, aboral ligament pit relatively large, oval and deep, axial canal rounded, clearly distinguishable on the other side of the transverse ridge. Adoral facet wide and high, with rounded corners, generally sunken, so that its base forms a plateau almost perpendicular to the aboral articular facet, muscle fossae subvertical, elliptical, relatively deep (Fig. 6.2, 6.5, 6.17). Aboral side wide, sometimes with very thick edge (Fig. 6.10), large and deep cavity, radial plate sutures more or less visible. Facet to column large, circular, with thin but clearly visible crenularium, which appears to be composed of long irregular tubercles in adults (Fig. 6.3, 6.10), and much shorter and regular tubercles in juveniles (Fig. 6.6). Lumen circular, moderately wide, large areola. Columnals barrel-shaped, with significant shape variation (Fig. 6.12, 6.14, 6.16), sometimes the same width throughout, sometimes much wider at mid-height, generally convex, articular surfaces with moderately wide lumen, thin crenularium, and large areola.

Remarks

The constriction at mid-height (Fig. 6.2) and the deep, wide aboral part of the cup (Fig. 6.3, 6.10) are characteristic of the species P. moussoni (de Loriol, Reference de Loriol1882–1884). The radial cavity of the specimens is moderately wide, but deep (Fig. 6.2, 6.10), as originally described by Desor (Reference Desor1845) and later considered by de Loriol (Reference de Loriol1882–1884). Other diagnostic features of the specimens are their large size in the adult stage, and their “cap-like appearance” (Desor, Reference Desor1845). This appearance is explained by a wide, very deep aboral cavity. The shape and structure of the radial articular facet (Fig. 6.17) agree with descriptions by de Loriol (Reference de Loriol1882–1884). Specimens show an important variability in different morphological characteristics, such as the size of the cup, the form of the aboral part (Fig. 6.3, 6.8, 6.10), the size of the interradial processes (Fig. 6.2, 6.7), their asymmetry, and the thickness of the cup (Fig. 6.3, 6.10), contradicting the explanations of Jaekel (Reference Jaekel1891). This phenomenon could be linked to an occurrence in shallow water, which could indicate adaptations to hydrodynamic regimes or stronger predation pressures, but this requires further study on a larger number of specimens. Columnals show a variety of shapes, but most often barrel-shaped, sometimes very wide (Fig. 6.12), convex, and their articular surface has a wide lumen with marginal tubercles arranged in a circle, whose organization seems to vary according to specimen size (Fig. 6.11, 6.13, 6.15). These characteristics correspond to specimens figured in Salamon (Reference Salamon2008) and Salamon et al. (Reference Salamon, Bubík, Ferré, Duda and Płachno2021).

Pilocrinus moussoni seems to be the only species of the genus Pilocrinus described from the Oxfordian and is very characteristic of this period (de Loriol, Reference de Loriol1882–1884; Jaekel, Reference Jaekel1891; Hess and Messing, Reference Hess and Messing2011), but some columnals have been described from the Callovian (Salamon, Reference Salamon2008), and others from the Cretaceous (Rasmussen, Reference Rasmussen1961). A cup of this species also has been recorded from the Campanian of Germany (Rasmussen, Reference Rasmussen1975). For some reason, some authors seem not to integrate the later discovery into the stratigraphic extension of the species (Hess and Messing, Reference Hess and Messing2011; Salamon et al., Reference Salamon, Bubík, Ferré, Duda and Płachno2021).

Type species

Ascidicrinus armatus Hess, Salamon, and Gorzelak, Reference Hess, Salamon and Gorzelak2011.

Diagnosis

Cups rather low, bulging or lobed interradially, especially in proximal view, commonly ornamented; radial articular facets broad, not sunken; radial cavity relatively deep, variable in diameter; facet for the column deep (after Hess et al., Reference Hess, Salamon and Gorzelak2011).

Lectotype

According to Žítt (Reference Žítt1974), cup from red marl of Štramberk, Czech Republic, early Lower Cretaceous (Jaekel, Reference Jaekel1891, pl. XXXVII, fig. 8).

Emended diagnosis

Cup low, pentagonal, generally smooth or very finely granular, with well-developed and robust interradial lobes in adoral part. Radial cavity narrow, moderately deep.

Occurrence

Late Jurassic, Oxfordian of Spain, Tithonian of Hungary, to Early Cretaceous (Berriasian–Valanginian) of France, Poland, Ukraine, and Czech Republic (Hess et al., Reference Hess, Salamon and Gorzelak2011).

Description

Rather small, low cup, slightly restricted at mid-height (Fig. 7.3, 7.7), aboral part wider than adoral part. Clearly pentagonal in oral and adoral views. Suture of radial plates generally slightly distinct but forms a very visible groove on the interradial lobes (Fig. 7.8). Smooth or slightly granular surface. Interradial lobes rather developed in basal part, very visible in lateral view, sometimes less indented in aboral view (Fig. 7.4). Interradial processes poorly developed, surrounding a small, fairly deep, circular to slightly pentagonal radial cavity with clearly visible adoral grooves. Articular facets of radial plates shallowly depressed and sloping outwards, aboral facet small, rounded or crescent-shaped, with fairly wide, subcircular aboral ligament pit, axial canal very small, rarely visible (Fig. 7.3, 7.7). Adoral facet wider and higher, rather trapezoidal (Fig. 7.2, 7.6), muscle fossae small, round when visible (Fig. 7.2). Aboral cavity pentagonal, wide, fairly deep, sutures of radial plates clearly visible, sometimes toothed (Fig. 7.4), facet to the column small but deep with crenulated edges.

Remarks

The pentagonal shape and the fairly distinct interradial lobes (Fig. 7.3, 7.7, 7.9) are the main characters that allow these specimens to be assigned to Ascidicrinus pentagonus. Other features such as the narrow radial cavity, aboral cavity, and general appearance of the specimen are in line with the description by Hess et al. (Reference Hess, Salamon and Gorzelak2011). Some specimens also correspond to the description of A. pentagonus from Manni et al. (Reference Manni, Nicosia and Szabó1992), in that the aboral articular facets are subvertical, crescent-shaped, with a wide aboral ligament pit and a small axial canal (Fig. 7.9). The adoral articular facet, on the other hand, is wider, with subcircular or circular muscular pits (Fig. 7.3) (Manni et al., Reference Manni, Nicosia and Szabó1992). This morphology of the facets supports the species determination of these specimens, even though the interarticular lobes are not as well developed, a feature already discussed by Hess et al. (Reference Hess, Salamon and Gorzelak2011). Finally, the surface of the specimens studied here appears to have little or no ornamentation (Fig. 7.3, 7.7), unlike the specimen of Manni et al. (Reference Manni, Nicosia and Szabó1992), but Hess et al. (Reference Hess, Salamon and Gorzelak2011) did not consider this as a characteristic of the species A. pentagonus. Moreover, A. pentagonus was also described as a small form, with no particular granulation by Jaekel (Reference Jaekel1891). The difference in ornamentation, added to the pentagonal shape of the specimen, easily distinguishes this species from Ascidicrinus armatus Hess, Salamon, and Gorzelak, Reference Hess, Salamon and Gorzelak2011.

The specimens described here, and particularly the smaller forms, resemble certain individuals of Gammarocrinites compressus by their adoral part and the general shape of their articular facet. However, the presence of interradial lobes in the aboral part is a diagnostic character of A. pentagonus. Thus, the attribution of these specimens to different species seems difficult. This discovery modifies the stratigraphic distribution of this species, making this the oldest known occurrence for A. pentagonus.

Type species

Sclerocrinus strambergensis Jaekel, Reference Jaekel1891.

Diagnosis

Cup mostly round, extremely massive; radial articular facet rounded, sloping strongly outward, with very small muscle fossae; radial cavity small. Facet to column large and deep, with differentiated inner part containing minute columnals (slightly modified after Hess and Messing, Reference Hess and Messing2011).

Occurrences

Late Jurassic (Oxfordian) of Spain, Tithonian of Czech Republic (Jaekel, Reference Jaekel1891), and Early Cretaceous (Valanginian) from Poland (Salamon and Gorzelak, Reference Salamon and Gorzelak2010b).

Description

Fairly large, compact cup, very wide and not very high, slightly asymmetrical. Wide and thick, convex-sided radial plates with flat lower edge and concave upper edge in lateral view (Fig. 7.12). Smooth cup surface with well-marked, straight or sometimes finely striated interradial sutures (Fig. 7.12, 7.13). Pentagonal adoral face with rounded rim, rather small radial cavity, a bit smaller than half the diameter of the cup, smooth rim. Deep, moderately narrow adoral grooves, interradial grooves inconspicuous (Fig. 7.10). Fairly well-developed interradial processes, surrounding a wide radial articular facet, whose edges meet the radial plate sutures. Aboral articular facet subvertical, crescent-shaped, rounded, not very high, sunken. Deep aboral ligament pit, moderately wide, subcircular or oval, more or less pronounced transverse ridge, thin, deep axial canal, slightly recessed, similar in size to the aboral ligament pit. Slightly high adoral articular facet, with a subhorizontal base, then, more vertical as the interradial processes rise, trapezoidal in shape with more or less rounded sides, fairly deep (Fig. 7.12). Muscle fossae almost subvertical in lateral view (Fig. 7.12), oblong or oval in adoral view (Fig. 7.10). Thick-edged, pentagonal aboral face with no visible lobes, surrounding a circular or elliptical, fairly wide and deep cavity with rather visible, sometimes raised sutures.

Remarks

The overall shape of the specimen combined with the thick radial plates that make it globular (Fig. 7.11, 7.12) are reminiscent of the S. strambergensis specimens described by Jaekel (Reference Jaekel1891) or Rasmussen (Reference Rasmussen1961). However, there are a number of characteristics that make species assignations problematic, such as the radial cavity, which is not as small as that of previously described specimens (Jaekel, Reference Jaekel1891; Rasmussen, Reference Rasmussen1961), the aboral face, which is not completely exposed (Fig. 7.13), making it impossible to observe the facets to the column. These features combined with the scarcity of material prevent a confident assignation to S. strambergensis.

This specimen differs from those of the Cyrtocrinus nutans and Gammarocrinites compressus in its large size, globular shape, the form of its radial articular facets, and its well-developed interradial processes. It also differs from the Pilocrinus moussoni specimens in that its adoral part is not raised and has straight edges; also, there is no constriction at mid-height, just the opposite, with the greatest width at this point. It differs from the Tithonian species Cyrtocrinus praenutans by the shape of its radial plates and by the size or the shape of the aboral cavity. The sutures of the specimen are sometimes slightly sinuous, giving patterns similar to those of G. compressus, C. praenutans, and P. moussoni, perhaps indicating that this feature may be peculiar to the Sclerocrinidae.

Type species

Eugeniacrinites moniliformis Münster in Goldfuss, Reference Goldfuss1826.

Diagnosis

Cup low, compact, with 3–6, commonly 4, radials, separated by a constriction and suture, more or less distinct from compact basal element, which may be discoidal, lenticular, barrel-shaped, or low subconical, resembling a columnal. Radial cavity moderate, continued in shallow central depression in basal element, generally less than half diameter of cup. Radial articular facet large and broad, occupying entire distal edge of cup and meeting along interradial sutures. Primibrachials 1 and 2 fused. Columnal articular facets with few crenulae or ridges, commonly in 4 groups (slightly modified after Hess and Messing, Reference Hess and Messing2011).

Lectotype

Basal circlet from the Jurassic of Streitberg (Oberfranken, Germany) (Münster in Goldfuss, Reference Goldfuss1826, p. 165, pl. LX, fig. 8l, m).

Diagnosis

Cup low, conical, well differentiated from the basal circlet. Basal circlet flat, strongly circular with a discoidal appearance and sometimes an enlarged top edge where granulation is located. Columnals varying in shape with fine and more or less regular granulation at mid-height, sometimes thorny. Aboral side of basal circlet and columnals with a large number of tubercles placed in a circle.

Occurrences

Middle Oxfordian of Spain, Callovian of Poland (Salamon and Feldman-Olszewska, Reference Salamon and Feldman-Olszewska2018), and Kimmeridgian of Czech Republic (Arendt, Reference Arendt1974).

Description

Small cup, rectangular in adoral view, with 4 radials surrounding a fairly deep, subrectangular radial cavity, relatively small in diameter (Fig. 8.1, 8.4). Radial plates not very high, convex, and bear a flat, almost horizontal adoral articular facet, as well as more outwardly inclined aboral articular facet with small and round axial canal, a slightly larger, oval aboral ligament pit, and a filiform transverse ridge. Cup can be found still articulated with the basal circles (Fig. 8.2, 8.5), and the suture seems quite deep and clearly discernible. Basal circlet flat, strongly circular with a discoidal appearance, rounded or sometimes with raised edge in lateral view (Fig. 8.2, 8.5, 8.8, 8.11), ornamented or smooth. Four crests running from center to outside of the circle in adoral view, with fairly small, shallow cavity. On some specimens (Fig. 8.10) the four ribs do not reach the outer edge of the basal circlet and the articulation facets for the radials are small, revealing a wide areola between these zones and the edge of the basal circlet. With these types of ossicles, basal circlet is wider than the rest of the cup, revealing part of its adoral side (Fig. 8.2). Aboral face flat or slightly concave, facet to the column comprises a small lumen (Fig. 8.9, 8.12), surrounded by a slightly wide areola and a crenularium composed of elongated tubercles, alternating with grooves, arranged in a circle (Fig. 8.6, 8.9, 8.12). Columnals cylindrical, convex laterally, sometimes discoid with almost triangular sides (Fig. 8.2), sometimes as high as wide, granulation at mid-height with tubercles more or less aligned, most of the time forming distinct spines (Fig. 8.13, 8.14). Articular surface smooth on the edges, with facet in the center featuring a small lumen and a few laterally flattened and regular granules on its contour (Fig. 8.13).

Remarks

This species is particularly recognizable by a cup with four radials well separated from a flat basal circlet (Fig. 8.2, 8.5). Disarticulated basal circlets are flat, bearing four ribs, sometimes the surface is marked with granulations, recalling the description of de Loriol (Reference de Loriol1879). The material described here shows considerable variability in terms of basal circlets and columnals, and some specimens also vary from those in the literature. Basal circlet varies from laterally rounded (Fig. 8.5, 8.8) to flanged (Fig. 8.2, 8.11). In plan view, articulation facet also changes and is sometimes restricted to the whole width of the basal circlet (Fig. 8.7), having in other cases a relatively wide epifacet (Fig. 8.10). These differences also have been described in the literature (see Jaekel, Reference Jaekel1892).

In terms of columnals, there is significant variation in ornamentation, with most of the columnals described here having ornamentation composed of tubercles transformed into long spines (Fig. 8.13, 8.14), while others have less developed ornamentation (Fig. 8.15, 8.16) or lack ornamentation. The shape of the columnals is also variable, but the first columnal still attached to the section (see Fig. 8.2) has a single row of spines that is different from material described in Hess and Messing (Reference Hess and Messing2011, fig. 96, 1a), which is barrel-shaped. However, despite all these variations on several types of T. moniliformis ossicles, this species was described by Jaekel, Reference Jaekel1892, as highly variable, reinforcing the idea that our specimens are included in this species. Further studies are still needed, with much more material.

All the specimens described here can be distinguished from Tetracrinus galei Hess, Reference Hess2014a, by the numerous tubercles surrounding the facet for the column in aboral view (Fig. 8.3, 8.6, 8.9, 8.11), its well-defined suture between the cup and the basal circlet, and by its extensive granulation (Fig. 8.13, 8.14). Tetracrinus moniliformis also has finer, more regular granulation on its stem articles than T. galei, whose ornamentation is more tessellated and irregular (Hess, Reference Hess2014a).