Pseudananchys supernus (Cragin, 1893)
Plate: PsSu-10
Series: Lower Cretaceous Group: Fredericksburg Formation: Goodland
Locale: Fort Worth County: Tarrant Stage: Albian
Length: 48.3 mm Width: 44.3 mm Height: 33.8 mm
Specimen in photo: NPL 83039 Hypotype
Collector: William R. Thompson, Jr.
University of Texas Non-vertebrate Paleo. Lab.
HOLOTYPE INFO:
Holotype: USNM 21644 (Cooke, 1953). Originally collected by J.S. Smith.
Locality: 7 miles south of Denton and 2 miles east of Argyle, Denton County, Texas (Cragin, 1893).
Stratigraphy: Goodland Limestone (Comanche Peak equivalent).
SYNONYMY
SYSTEMATIC PALEONTOLOGY – TAXONOMY
Class: Echinoidea Leske, 1778
Subclass: Euechinoidea Bronn, 1860
Infraclass: Irregularia Latreille, 1825
Superorder: Atelostomata Zittel, 1879
Order: Holasteroida Durham, 1957
Family: Holasteridae Pictet, 1857
Genus: PSEUDANANCHYS Pomel, 1883
Species: Pseudananchys supernus (Cragin, 1893)
TYPE SPECIES: Ananchytes algirus Coquand, 1862
DIAGNOSIS
Test large, round, and elevated. Characterized by a "top-heavy" profile where the lateral wall is most inflated above the middle, tapering downward below the line of maximum inflation. Pores of the unpaired ambulacrum are slit-like and similar to those of the paired ambulacra (Cragin, 1893).
STRATIGRAPHICAL OCCURRENCE & DISTRIBUTION
Group: Fredericksburg
Formations: Goodland Limestone.
Stratigraphic Units: Lower Cretaceous, Albian.
Counties: Tarrant, Denton.
Abundance: Rare.
DESCRIPTION
TOP: Length, width, height: 48.3 mm L × 44.3 mm W × 33.8 mm H. Top shape: Ovate/Round; widest at midpoint. Periproct not visible from above.
SIDE: Side shape: Very inflated, globular; described as "top-heavy" in the type. Ambitus: Positioned low (30% from adoral surface); lateral walls taper downward. Profile: Posterior end has a very slight point; periproct makes a pronounced cut into the posterior end below the ambitus.
BOTTOM: Bottom shape: Somewhat flat, but convex.
AMB: Amb shape: Lanceolate. Unpaired ambulacrum runs from apical system to very near the anterior end; paired ambulacra run about 3/4 down the sides. Lower part of anterior ambulacrum is slightly flattened and feebly concave at the margin (Cragin, 1893). Amb arrangement: Pores of the unpaired ambulacrum are similar and equal to those of the paired ones.
PORE PAIRS: Shape: In paired ambulacra, outer pores are elongated, inner pores slightly elongated. In unpaired ambulacrum, pairs consist of one short and one long slit-like sub-horizontal pore (Cragin, 1893). Arrangement: Just above the margin, pore pair spacing increases, and pores become smaller, shorter (dot-like), and tighter (Book Author; Cragin, 1893).
TUBERCLES: Primary Perforated: Yes. Primary Crenulate: Yes. Distribution: Largest on the bottom; sparse on the adoral surface.
GRANULES: (Not specified).
FASCIOLE: Absent in Pseudananchys.
APICAL SYSTEM: Location: Slightly posterior of center. Plating: Madreporic function divided among several plates (Cragin, 1893).
PERIPROCT (ANUS): Shape: Teardrop; small for the size of the test. Location: Low on the posterior face (about 20% from adoral surface).
PERISTOME (MOUTH): Shape: Sub-pentagonal; "half sub-spherical" (semicircular). Size: Depressed; slightly smaller than the periproct. Visibility: Only slightly visible from the anterior end.
SPINES: Unknown.
SPECIMENS STUDIED & CONDITION: Hypotype NPL 83039.
ETYMOLOGY
From the Latin supernus (upper, celestial, or high), likely referring to the elevated, top-heavy profile of the holotype.
REMARKS & COMPARISONS
Remarks: Cragin (1893) noted that P. supernus is closely related to Pseudananchys completa (Holaster completus), hypothesizing they might represent age variants of a single species. Cooke (1953) formalized this synonymy, placing supernus under P. completa. However, the "top-heavy" profile described by Cragin and the specific pore arrangement are traits used here to maintain it as distinct.
Comparisons:
Remarks (01-2026): The Hypotype described here (Height 33.8 mm) is significantly less "top-heavy" and elevated than Cragin's Holotype (Height 53.5 mm). This variation supports Cragin's original hypothesis that supernus might be the adult/senile phase of completa, or suggests the Hypotype might be intermediate.
Plate: PsSu-10
Series: Lower Cretaceous Group: Fredericksburg Formation: Goodland
Locale: Fort Worth County: Tarrant Stage: Albian
Length: 48.3 mm Width: 44.3 mm Height: 33.8 mm
Specimen in photo: NPL 83039 Hypotype
Collector: William R. Thompson, Jr.
University of Texas Non-vertebrate Paleo. Lab.
HOLOTYPE INFO:
Holotype: USNM 21644 (Cooke, 1953). Originally collected by J.S. Smith.
Locality: 7 miles south of Denton and 2 miles east of Argyle, Denton County, Texas (Cragin, 1893).
Stratigraphy: Goodland Limestone (Comanche Peak equivalent).
SYNONYMY
- Holaster supernus Cragin, 1893
- Pseudananchys completa (Cragin) (fide Cooke, 1953; in part)
SYSTEMATIC PALEONTOLOGY – TAXONOMY
Class: Echinoidea Leske, 1778
Subclass: Euechinoidea Bronn, 1860
Infraclass: Irregularia Latreille, 1825
Superorder: Atelostomata Zittel, 1879
Order: Holasteroida Durham, 1957
Family: Holasteridae Pictet, 1857
Genus: PSEUDANANCHYS Pomel, 1883
Species: Pseudananchys supernus (Cragin, 1893)
TYPE SPECIES: Ananchytes algirus Coquand, 1862
DIAGNOSIS
Test large, round, and elevated. Characterized by a "top-heavy" profile where the lateral wall is most inflated above the middle, tapering downward below the line of maximum inflation. Pores of the unpaired ambulacrum are slit-like and similar to those of the paired ambulacra (Cragin, 1893).
STRATIGRAPHICAL OCCURRENCE & DISTRIBUTION
Group: Fredericksburg
Formations: Goodland Limestone.
Stratigraphic Units: Lower Cretaceous, Albian.
Counties: Tarrant, Denton.
Abundance: Rare.
DESCRIPTION
TOP: Length, width, height: 48.3 mm L × 44.3 mm W × 33.8 mm H. Top shape: Ovate/Round; widest at midpoint. Periproct not visible from above.
SIDE: Side shape: Very inflated, globular; described as "top-heavy" in the type. Ambitus: Positioned low (30% from adoral surface); lateral walls taper downward. Profile: Posterior end has a very slight point; periproct makes a pronounced cut into the posterior end below the ambitus.
BOTTOM: Bottom shape: Somewhat flat, but convex.
AMB: Amb shape: Lanceolate. Unpaired ambulacrum runs from apical system to very near the anterior end; paired ambulacra run about 3/4 down the sides. Lower part of anterior ambulacrum is slightly flattened and feebly concave at the margin (Cragin, 1893). Amb arrangement: Pores of the unpaired ambulacrum are similar and equal to those of the paired ones.
PORE PAIRS: Shape: In paired ambulacra, outer pores are elongated, inner pores slightly elongated. In unpaired ambulacrum, pairs consist of one short and one long slit-like sub-horizontal pore (Cragin, 1893). Arrangement: Just above the margin, pore pair spacing increases, and pores become smaller, shorter (dot-like), and tighter (Book Author; Cragin, 1893).
TUBERCLES: Primary Perforated: Yes. Primary Crenulate: Yes. Distribution: Largest on the bottom; sparse on the adoral surface.
GRANULES: (Not specified).
FASCIOLE: Absent in Pseudananchys.
APICAL SYSTEM: Location: Slightly posterior of center. Plating: Madreporic function divided among several plates (Cragin, 1893).
PERIPROCT (ANUS): Shape: Teardrop; small for the size of the test. Location: Low on the posterior face (about 20% from adoral surface).
PERISTOME (MOUTH): Shape: Sub-pentagonal; "half sub-spherical" (semicircular). Size: Depressed; slightly smaller than the periproct. Visibility: Only slightly visible from the anterior end.
SPINES: Unknown.
SPECIMENS STUDIED & CONDITION: Hypotype NPL 83039.
ETYMOLOGY
From the Latin supernus (upper, celestial, or high), likely referring to the elevated, top-heavy profile of the holotype.
REMARKS & COMPARISONS
Remarks: Cragin (1893) noted that P. supernus is closely related to Pseudananchys completa (Holaster completus), hypothesizing they might represent age variants of a single species. Cooke (1953) formalized this synonymy, placing supernus under P. completa. However, the "top-heavy" profile described by Cragin and the specific pore arrangement are traits used here to maintain it as distinct.
Comparisons:
- Pseudananchys completa: P. supernus is distinguished by being "top-heavy" (lateral walls bulging in the upper part and tapering inferiorly), whereas P. completa typically has a lower test and different lateral wall inflation (Cragin, 1893).
Remarks (01-2026): The Hypotype described here (Height 33.8 mm) is significantly less "top-heavy" and elevated than Cragin's Holotype (Height 53.5 mm). This variation supports Cragin's original hypothesis that supernus might be the adult/senile phase of completa, or suggests the Hypotype might be intermediate.
