Euryocrinidae Moore & Strimple, 1973

Family Euryocrinidae Moore & Strimple, 1973 Genus Dieuryocrinus Wright, 1954

Type species: Euryocrinus duplex Wright, 1942 , by original designation. Coplow Knoll , Clitheroe , UK; Mississippian (upper Tournaisian) .

Stratigraphic and geographic range.—Viséan, Mississippian, Carboniferous, UK and questionably Artinskian, Cisuralian, Permian, Slovenia.

Dieuryocrinus ? sp. Fig. 4A View Fig .

Material.—GMJ: PAL- 0000368, well-preserved partial calyx; Trogkofel Group, Permian (middle to upper Artinskian), near Dovje, Slovenia.

Description.—Calyx large in size; flat cone shape; plates flat to gently convex, smooth plate sculpturing. Infrabasal circlet plate and basal plate circlets not preserved and only distal-most portion of two radial plates visible. CD interray unknown. Regular interrays with one relatively small, pentagonal first interradial plate supporting two interradial plates above, regular interray plating 1-2-2-2-2-2-2-?; interray plates above the first interradial plate are hexagonal and diminish in size distally. Oral surface and anal sac unknown. Brachials fixed through at least the fifth secundibrachial. First secundibrachial hexagonal, wider than high; second primibrachial axillary, heptagonal, wider than high. Fixed secundibrachials wider than high. Fixed intrabrachials present between fixed secundibrachials, arranged 1-2-2- 2-2-?. Free arms and column unknown.

Measurements. —CaW, 8.9*.

Remarks. —Previously, Dieuryocrinus was only known from Viséan strata of the United Kingdom, so if this questioned generic assignment proves correct, this Slovenian occurrence greatly expands the temporal and geographic range of this genus. The generic assignment is questioned because only a partial crown of Dieuryocrinus ? sp. is preserved. Taxonomically useful attributes of this specimen are a low to flat bowl-shaped calyx, fixed calyx plates through at least the proximal tertibrachials, two primibrachials, three or more secundibrachials, absence of patelloid processes on fixed brachial plates, first interradial plate followed by two columns of interradial plates, and fixed intrabrachial plates separating second secundibrachials and higher fixed brachials. Important morphological information missing on this specimen is the nature of the proximal column, plating in the posterior interray, extent of fixed brachials, and characters of the free brachials.

Most Permian flexible crinoids belong to specialized clades, such as the Calycocrinidae, Mespilocrinidae , Palaeoholopidae, and Prophyllocrinidae . This flexible crinoid from Slovenia is more typical of Permian Sagenocrinitoidea with numerous fixed brachials and intrabrachial plates. Previously four sagenocrinitoid genera have been described from Permian strata note, as listed in Webster and Webster (2014), Forbesiocrinus siculus Gregario, 1930 , does not belong to the Forbesiocrinus ).

The Slovenian flexible crinoid is most similar to two genera in the Euryocrinidae : Caldenocrinus Wright, 1946 , and Dieuryocrinus Wright, 1954 (both Viséan, Scotland) that lack patelloid processes and have both interradial and intrabrachial plates. With a double row of interradial plates and several intrabrachial plates, this flexible crinoid is most similar to Dieuryocrinus and is assigned to Dieuryocrinus ? sp., which may extend the range of this genus into the lower Permian. The generic assignment is questioned and a species is not named because key morphological characters of this taxon remain unknown.

Superorder Cyathoformes Wright et al., 2017 Cyathoformes incertae sedis “Poteriocrinida” Jaekel, 1918

Superfamily Erisocrinoidea Wachsmuth & Springer, 1886

Family Stachyocrinidae Moore & Strimple, 1973

Remarks. — Moore and Strimple (1973: 22) erected the Stachyocrinidae to include erisocrinoids with a cylindrical to ovoid crown, low bowl to saucer-shaped aboral cups with a shallow basal concavity, proximal tips of the radial plates reaching the basal plate or well above it, primanal not visible from the exterior of the cup in lateral view, ten arms with rectilinear uniserial brachials, and a circular proximal column. They included Stachyocrinus Wanner, 1916 , and Parastachyocrinus Wanner, 1937 , with Stachyocrinus having aboral cups with the basal plates not visible in lateral view, whereas the basal plates are clearly visible in Parastachyocrinus .

Two specimens ( Fig. 5C and F View Fig ) from the Trogkofel Group are placed in the Stachyocrinidae because they have a very low bowl-shaped aboral cup with infrabasals partly in a shallow basal concavity and not visible in lateral view, modestly convex basal plates, plenary radial facets, and no posterior plates visible in lateral view of the aboral cup. This new material is placed within Parastachyocrinus because the basal plates are not confined to the base of the aboral cup and are visible in lateral view.

As presently understood, species-level systematics within Parastachyocrinus is very poorly defined and is revised herein.First, species currently assigned to Parastachyocrinus have a wide range of morphologies that would more typically be indicative of more than one genus. Second, the morphology of the type species requires emphasis.

Intheinitialdescriptionof Erisocrinus malaianus Wanner, 1924 , two morphotypes were illustrated (“Exemplar a” and “Exemplar b”). “Exemplar a” has very convex and/or spinose basal and radial plates ( Wanner 1924: pl. 18: 25–27), and he referred to this specimen as the holotype (herein “Exemplar a” of Erisocrinus malaianus Wanner, 1924 , is regarded as the holotype of the type species of Parastachyocrinus ). Wanner (1924: pl. 18: 22–24) illustrated a second morphology as “Exemplar b”. This specimen has an aboral cup of similar shape to “Exemplar a”, but the aboral cup plates are only moderately convex and nodes and spines are absent. Wanner (1924) also described Erisocrinus obliquus and illustrated five specimens (“Exemplar a” to “Exemplar d”). As noted below, Erisocrinus obliquus was subsequently reassigned to Parastachyocrinus .

In 1949, Wanner erected Parastachyocrinus , designated Erisocrinus malaianus Wanner, 1924 , as its type species, and listed Wanner (1924: pl. 18: 22–27), both “Exemplar a” and “Exemplar b” to refer to the morphology of Parastachyocrinus malaianus . However, Wanner (1949) did not re-illustrate “Examplar a”. Instead, he illustrated five additional specimens of P. malaianus , “Exemplar c” to “Exemplar g” ( Wanner 1949: pl. 3: 10–17). He also introduced P. malaianus var. ornata ( Wanner 1949: pl. 3: 18–19), which was subsequently corrected to P. malaianus ornatus by Webster and Webster (2014).

Also in 1949, Wanner reassigned Erisocrinus granulatus Wanner, 1924 , and Erisocrinus obliquus Wanner, 1916 , to Parastachyocrinus and named the new species P. inflatus Wanner, 1949 . Finally, Moore et al. (1978: fig. 475.1) illustrated two specimens of P. malaianus , “Exemplar a” and “Exemplar c”, which are very dissimilar in morphology, but designated “Exemplar a” as the “ holotype ” in the figure explanation.

In summary, Webster and Webster (2014) recognized five species-level taxa in Parastachyocrinus , and two new species are recognized herein.