Pygopyrina hancockensis (Whitney and Kellum, 1966)
Plate: PyHa-10
Series: Lower Cretaceous Group: Trinity Formation: Glen Rose
Locale: Hancock County: Comal Stage: Early Albian
Length: 22.3 mm Width: 18.6 mm Height: 14.2 mm
Specimen in photos: Collection of Ed Elliot
Repository: Private Collection
Plate: PyHa-20
Series: Lower Cretaceous Group: Trinity Formation: Glen Rose
Locale: Canyon Lake County: Comal Stage: Early Albian
Length: 11.8 mm Width: 9.6 mm Height: 6.2 mm
Specimen in photos: Collection of Ed Elliot Juvenile
Repository: Private Collection
HOLOTYPE INFO:
Holotype: UMMP 52169 (University of Michigan Museum of Paleontology) (Whitney & Kellum, 1966).
Locality: 2 miles southwest of Wimberley, Hays County, Texas.
Stratigraphy: Glen Rose Formation (Lower Member), Trinity Group.
SYNONYMY
SYSTEMATIC PALEONTOLOGY – TAXONOMY
Class: Echinoidea Leske, 1778
Subclass: Euechinoidea Bronn, 1860
Infraclass: Irregularia Latreille, 1825
Superorder: Neognathostomata Smith, 1981
Order: Cassiduloida Claus, 1880
Family: Nucleolitidae L. Agassiz & Desor, 1847
Genus: PYGOPYRINA Pomel, 1883
Species: Pygopyrina hancockensis (Whitney & Kellum, 1966)
TYPE SPECIES: Nucleolites pusillus Agassiz, 1847
DIAGNOSIS
Test small to medium, ovate, and inflated (subglobular). The periproct is supramarginal and teardrop-shaped. The peristome is oblique. Distinguished from Globator by the absence of a distinct anal sulcus connecting the periproct to the margin (Smith & Rader, 2009).
STRATIGRAPHICAL OCCURRENCE & DISTRIBUTION
Group: Trinity
Formations: Glen Rose Formation (Lower Glen rose, Unit 2.)
Stratigraphic Units: Lower Cretaceous, Aptian.
Counties: Comal, Hays.
Abundance: Large specimens rare. Small specimens scarce.
DESCRIPTION
TOP: Length, width, height: 22.3 mm L × 18.6 mm W × 14.2 mm H (Adult). Top shape: Ovate; equally wide throughout the middle of the test; posterior margin shows less curvature. Top domed: Slightly bulbous in adults.
SIDE: Ambitus: Positioned about 45% of height from the adoral surface. Side shape: Test egg-shaped; inflated. Profile: Apex located posterior of center (about 25% from posterior margin).
BOTTOM: Bottom shape: Convex adoral surface (Whitney & Kellum, 1966).
AMB: Amb shape: Lanceolate; widest at the margin, narrowing at the peristome. Raised from the test surface (more so on adults).
PORE PAIRS: Arrangement: Uniserial; becoming offset as they near the peristome.
TUBERCLES: Distribution: Primary tubercles cover the entire test evenly, with some thinning in the ambulacra; tubercles are slightly larger on the adoral side. Features: Small and sunken.
GRANULES: Distribution: Dense granulation fills the spaces between tubercles.
FASCIOLE: Absent.
APICAL SYSTEM: Location: Slightly anterior of center. Genital pores: Four perforated pores.
PERIPROCT (ANUS): Shape: Teardrop shaped; more elongated in juveniles than in adults. Location: Supramarginal (visible from above). Position shifts ontogenetically: located at the midpoint between the posterior margin and apical system in juveniles, moving close to the posterior margin in adults.
PERISTOME (MOUTH): Shape: Oval. Orientation: Sits longitudinally and slightly oblique (characteristic of the genus). Location: Slightly posterior of midpoint in adults.
SPINES: Unknown.
SPECIMENS STUDIED & CONDITION:
ETYMOLOGY
Named for the Hancock, a historic community in northern Comal County. Designated by Whitney & Kellum (1966).
REMARKS & COMPARISONS
Remarks: Whitney & Kellum (1966) originally assigned this species to Globator. Smith & Rader (2009) transferred it to Pygopyrina, noting that Globator typically possesses a sulcus extending from the periproct, which this species lacks. The Book Author notes a distinct ontogenetic shift in the position of the periproct, moving posteriorly as the individual matures.
Comparisons:
Plate: PyHa-10
Series: Lower Cretaceous Group: Trinity Formation: Glen Rose
Locale: Hancock County: Comal Stage: Early Albian
Length: 22.3 mm Width: 18.6 mm Height: 14.2 mm
Specimen in photos: Collection of Ed Elliot
Repository: Private Collection
Plate: PyHa-20
Series: Lower Cretaceous Group: Trinity Formation: Glen Rose
Locale: Canyon Lake County: Comal Stage: Early Albian
Length: 11.8 mm Width: 9.6 mm Height: 6.2 mm
Specimen in photos: Collection of Ed Elliot Juvenile
Repository: Private Collection
HOLOTYPE INFO:
Holotype: UMMP 52169 (University of Michigan Museum of Paleontology) (Whitney & Kellum, 1966).
Locality: 2 miles southwest of Wimberley, Hays County, Texas.
Stratigraphy: Glen Rose Formation (Lower Member), Trinity Group.
SYNONYMY
- Globator hancockensis Whitney & Kellum, 1966
- Pygopyrina hancockensis (Whitney & Kellum) Smith & Rader, 2009
SYSTEMATIC PALEONTOLOGY – TAXONOMY
Class: Echinoidea Leske, 1778
Subclass: Euechinoidea Bronn, 1860
Infraclass: Irregularia Latreille, 1825
Superorder: Neognathostomata Smith, 1981
Order: Cassiduloida Claus, 1880
Family: Nucleolitidae L. Agassiz & Desor, 1847
Genus: PYGOPYRINA Pomel, 1883
Species: Pygopyrina hancockensis (Whitney & Kellum, 1966)
TYPE SPECIES: Nucleolites pusillus Agassiz, 1847
DIAGNOSIS
Test small to medium, ovate, and inflated (subglobular). The periproct is supramarginal and teardrop-shaped. The peristome is oblique. Distinguished from Globator by the absence of a distinct anal sulcus connecting the periproct to the margin (Smith & Rader, 2009).
STRATIGRAPHICAL OCCURRENCE & DISTRIBUTION
Group: Trinity
Formations: Glen Rose Formation (Lower Glen rose, Unit 2.)
Stratigraphic Units: Lower Cretaceous, Aptian.
Counties: Comal, Hays.
Abundance: Large specimens rare. Small specimens scarce.
DESCRIPTION
TOP: Length, width, height: 22.3 mm L × 18.6 mm W × 14.2 mm H (Adult). Top shape: Ovate; equally wide throughout the middle of the test; posterior margin shows less curvature. Top domed: Slightly bulbous in adults.
SIDE: Ambitus: Positioned about 45% of height from the adoral surface. Side shape: Test egg-shaped; inflated. Profile: Apex located posterior of center (about 25% from posterior margin).
BOTTOM: Bottom shape: Convex adoral surface (Whitney & Kellum, 1966).
AMB: Amb shape: Lanceolate; widest at the margin, narrowing at the peristome. Raised from the test surface (more so on adults).
PORE PAIRS: Arrangement: Uniserial; becoming offset as they near the peristome.
TUBERCLES: Distribution: Primary tubercles cover the entire test evenly, with some thinning in the ambulacra; tubercles are slightly larger on the adoral side. Features: Small and sunken.
GRANULES: Distribution: Dense granulation fills the spaces between tubercles.
FASCIOLE: Absent.
APICAL SYSTEM: Location: Slightly anterior of center. Genital pores: Four perforated pores.
PERIPROCT (ANUS): Shape: Teardrop shaped; more elongated in juveniles than in adults. Location: Supramarginal (visible from above). Position shifts ontogenetically: located at the midpoint between the posterior margin and apical system in juveniles, moving close to the posterior margin in adults.
PERISTOME (MOUTH): Shape: Oval. Orientation: Sits longitudinally and slightly oblique (characteristic of the genus). Location: Slightly posterior of midpoint in adults.
SPINES: Unknown.
SPECIMENS STUDIED & CONDITION:
- Adult (Plate PyHa-10): Length 22.3 mm. Hancock, Comal Co. Collection of Ed Elliott.
- Juvenile (Plate PyHa-20): Length 11.8 mm. Canyon Lake, Comal Co. Collection of Ed Elliott.
ETYMOLOGY
Named for the Hancock, a historic community in northern Comal County. Designated by Whitney & Kellum (1966).
REMARKS & COMPARISONS
Remarks: Whitney & Kellum (1966) originally assigned this species to Globator. Smith & Rader (2009) transferred it to Pygopyrina, noting that Globator typically possesses a sulcus extending from the periproct, which this species lacks. The Book Author notes a distinct ontogenetic shift in the position of the periproct, moving posteriorly as the individual matures.
Comparisons:
- Pygopyrina vs. Globator: P. hancockensis lacks the anal sulcus of Globator.
