Pedinopsis pondi Clark, 1893
Plate: PePo-10
Series: Upper Cretaceous Group: Austin Formation: Austin Chalk
Locale: Austin County: Travis Stage: Santonian
Length: 88.6 mm Height: 59.7 mm
Specimen in photos: U.S.N.M. 103707 Holotype
Collector: USGS SURVEY
Repository: Paleobiology Dept., NMNH, Smithsonian Institution
Plate: PePo-20
Series: Upper Cretaceous Group: Washita Formation: Buda
Locale: Manchacha County: Travis Stage: Cenomanian
Length: 70 mm Height: 39 mm
Collection: Lee Schnelle
HOLOTYPE INFO:
Holotype: USNM 103707 (Clark, 1893).
Locality: Austin, Travis County, Texas.
Stratigraphy: Recorded as Austin Chalk (Cooke, 1953); likely Buda Limestone based on recent findings (Schnelle, pers. comm.).
SYSTEMATIC PALEONTOLOGY – TAXONOMY
Class: Echinoidea Leske, 1778
Subclass: Euechinoidea Bronn, 1860
Infraclass: Carinacea Kroh & Smith, 2010
Superorder: Calycina Gregory, 1900
Order: Phymosomatoida Mortensen, 1904
Family: Pedinopsidae Durham, 1955
Genus: PEDINOPSIS Cotteau, 1863
Species: Pedinopsis pondi Clark, 1893
TYPE SPECIES: Pedinopsis meridanensis Cotteau, 1863
DIAGNOSIS
Test large, highly inflated, and subglobular. Ambulacra are narrow with compound plates bearing 6 pore pairs above the ambitus and 4 below. Pore zones are biserial above the ambitus. Tubercles are small, perforate, crenulate, and numerous, arranged in horizontal rows (Clark, 1915; Cooke, 1953).
STRATIGRAPHICAL OCCURRENCE & DISTRIBUTION
Group: Austin (Historical); Washita (Revised).
Formations: Austin Chalk (Type); Buda Limestone / Del Rio Clay contact (New occurrence).
Stratigraphic Units: Upper Cretaceous, Santonian (Type label) or Cenomanian (New occurrence).
Counties: Travis.
Abundance: Rare; historically known only from the type until recent collections.
DESCRIPTION
TOP: Length, width, height: 88.6 mm L × 59.7 mm H (Holotype). Top shape: Horizontal outline nearly circular. Top domed: Highly inflated; margin broadly rounded.
SIDE: Side shape: Subglobular; "melon shaped".
BOTTOM: Bottom shape: Flattened on the lower surface.
AMB: Amb shape: Narrow. Amb arrangement: Plates are compound. Six pairs of pores to each compound plate above the ambitus; four pairs below it (Cooke, 1953). Tubercles arranged in even horizontal rows; four on each ambulacral plate at the ambitus.
PORE PAIRS: Arrangement: Plainly biserial above the ambitus. Below the ambitus, the series are compressed and overlapping, showing a tendency to arrangement in diagonal groups of four pairs. Biserial near the peristome with pores slightly multiplied (Cooke, 1953).
TUBERCLES: Primary Perforated: Yes. Primary Crenulate: Yes. Distribution: Small and inconspicuous (or eroded on upper part). Arranged in even, horizontal rows on and below the ambitus.
INTERAMB: Arrangement: Coronal plates short and very wide. As many as ten tubercles on each interambulacral plate at the ambitus (Cooke, 1953). Shape: Interambulacral plates bulge outward.
FASCIOLE: Absent.
APICAL SYSTEM: Size: Not very large; diameter not more than 11 mm. Condition: Unknown in type (Cooke, 1953).
PERIPROCT (ANUS): (Unknown).
PERISTOME (MOUTH): Size: Small; diameter 23 mm. Shape: Nearly circular. Lip: Weakly notched.
SPINES: Unknown.
SPECIMENS STUDIED & CONDITION:
ETYMOLOGY
Named for the collector or a colleague of W.B. Clark (specific etymology not listed in original text, but likely a patronym).
REMARKS & COMPARISONS
Remarks: Cooke (1953) noted this species was known only from the type and assigned it to the Austin Chalk. However, field evidence provided by Lee Schnelle regarding a new specimen from Manchaca, Texas, suggests the species may actually originate from the Buda Limestone (Cenomanian) or the uppermost Del Rio Clay. Schnelle notes the specimen was embedded in the uppermost Del Rio with basal Buda storm deposits nearby, and the nearest Austin Chalk was 0.75 miles away. This suggests the original "Austin Chalk" locality label for the holotype may have referred to the city of Austin geography rather than the specific formation, or the range extends significantly.
Comparisons:
Plate: PePo-10
Series: Upper Cretaceous Group: Austin Formation: Austin Chalk
Locale: Austin County: Travis Stage: Santonian
Length: 88.6 mm Height: 59.7 mm
Specimen in photos: U.S.N.M. 103707 Holotype
Collector: USGS SURVEY
Repository: Paleobiology Dept., NMNH, Smithsonian Institution
Plate: PePo-20
Series: Upper Cretaceous Group: Washita Formation: Buda
Locale: Manchacha County: Travis Stage: Cenomanian
Length: 70 mm Height: 39 mm
Collection: Lee Schnelle
HOLOTYPE INFO:
Holotype: USNM 103707 (Clark, 1893).
Locality: Austin, Travis County, Texas.
Stratigraphy: Recorded as Austin Chalk (Cooke, 1953); likely Buda Limestone based on recent findings (Schnelle, pers. comm.).
SYSTEMATIC PALEONTOLOGY – TAXONOMY
Class: Echinoidea Leske, 1778
Subclass: Euechinoidea Bronn, 1860
Infraclass: Carinacea Kroh & Smith, 2010
Superorder: Calycina Gregory, 1900
Order: Phymosomatoida Mortensen, 1904
Family: Pedinopsidae Durham, 1955
Genus: PEDINOPSIS Cotteau, 1863
Species: Pedinopsis pondi Clark, 1893
TYPE SPECIES: Pedinopsis meridanensis Cotteau, 1863
DIAGNOSIS
Test large, highly inflated, and subglobular. Ambulacra are narrow with compound plates bearing 6 pore pairs above the ambitus and 4 below. Pore zones are biserial above the ambitus. Tubercles are small, perforate, crenulate, and numerous, arranged in horizontal rows (Clark, 1915; Cooke, 1953).
STRATIGRAPHICAL OCCURRENCE & DISTRIBUTION
Group: Austin (Historical); Washita (Revised).
Formations: Austin Chalk (Type); Buda Limestone / Del Rio Clay contact (New occurrence).
Stratigraphic Units: Upper Cretaceous, Santonian (Type label) or Cenomanian (New occurrence).
Counties: Travis.
Abundance: Rare; historically known only from the type until recent collections.
DESCRIPTION
TOP: Length, width, height: 88.6 mm L × 59.7 mm H (Holotype). Top shape: Horizontal outline nearly circular. Top domed: Highly inflated; margin broadly rounded.
SIDE: Side shape: Subglobular; "melon shaped".
BOTTOM: Bottom shape: Flattened on the lower surface.
AMB: Amb shape: Narrow. Amb arrangement: Plates are compound. Six pairs of pores to each compound plate above the ambitus; four pairs below it (Cooke, 1953). Tubercles arranged in even horizontal rows; four on each ambulacral plate at the ambitus.
PORE PAIRS: Arrangement: Plainly biserial above the ambitus. Below the ambitus, the series are compressed and overlapping, showing a tendency to arrangement in diagonal groups of four pairs. Biserial near the peristome with pores slightly multiplied (Cooke, 1953).
TUBERCLES: Primary Perforated: Yes. Primary Crenulate: Yes. Distribution: Small and inconspicuous (or eroded on upper part). Arranged in even, horizontal rows on and below the ambitus.
INTERAMB: Arrangement: Coronal plates short and very wide. As many as ten tubercles on each interambulacral plate at the ambitus (Cooke, 1953). Shape: Interambulacral plates bulge outward.
FASCIOLE: Absent.
APICAL SYSTEM: Size: Not very large; diameter not more than 11 mm. Condition: Unknown in type (Cooke, 1953).
PERIPROCT (ANUS): (Unknown).
PERISTOME (MOUTH): Size: Small; diameter 23 mm. Shape: Nearly circular. Lip: Weakly notched.
SPINES: Unknown.
SPECIMENS STUDIED & CONDITION:
- Holotype USNM 103707: Austin Chalk, Austin, TX.
- Specimen 2: Collection of Lee Schnelle. Length 70 mm. Manchaca, TX. Found at Buda/Del Rio contact.
ETYMOLOGY
Named for the collector or a colleague of W.B. Clark (specific etymology not listed in original text, but likely a patronym).
REMARKS & COMPARISONS
Remarks: Cooke (1953) noted this species was known only from the type and assigned it to the Austin Chalk. However, field evidence provided by Lee Schnelle regarding a new specimen from Manchaca, Texas, suggests the species may actually originate from the Buda Limestone (Cenomanian) or the uppermost Del Rio Clay. Schnelle notes the specimen was embedded in the uppermost Del Rio with basal Buda storm deposits nearby, and the nearest Austin Chalk was 0.75 miles away. This suggests the original "Austin Chalk" locality label for the holotype may have referred to the city of Austin geography rather than the specific formation, or the range extends significantly.
Comparisons:
- Pedinopsis molineuxae: P. pondi is more "melon shaped" with bulging interambulacral plates and a more pointed lateral profile, whereas P. molineuxae is more pentagonal and rounded laterally. The primary tubercles in P. pondi are much smaller than those of P. molineuxae, and the peristome is proportionally smaller.
