Hardouinia bassleri (Twitchell, 1915)
Plate: HaBa-10
Series: Upper Cretaceous Group: Taylor Formation: Anacacho Limestone
Locale: Muela Creek County: Kinney Stage: Campanian
Length: 24.3 mm Width: 22.7 mm Height: 10.7 mm
Specimen in photo: U.S.N.M. PAL479792 Type
Paleobiology Depart. NMNH, Smithsonian Institution
HOLOTYPE INFO:
Holotype: USNM 103863 (Twitchell, 1915) — National Museum of Natural History, Smithsonian Institution
Locality: Plymouth, North Carolina (Twitchell, 1915)
Stratigraphy: Eutaw Formation equivalents (Upper Cretaceous) (Cooke, 1953)
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: Faujasiidae Lambert, 1905
Genus: HARDOUINIA Haime, 1853
Species: Hardouinia bassleri (Twitchell, 1915)
TYPE SPECIES: Hardouinia potosiensis Lambert, 1911
DIAGNOSIS
Test small, subovate to subcircular, broadest posteriorly. Periproct supramarginal, situated in a depression above the posterior rostration. Petals lanceolate; bourrelets conspicuous, blunt, and hollow (Twitchell, 1915; Cooke, 1953).
STRATIGRAPHICAL OCCURRENCE & DISTRIBUTION
Group: Taylor
Formations: Anacacho Limestone (Texas); Eutaw/McShan equivalents (North Carolina)
Stratigraphic Units: Upper Cretaceous, Campanian
Counties: Kinney County (Texas)
DESCRIPTION
TOP: Length, width, height: 24.3 mm L × 22.7 mm W × 10.7 mm H
Top shape: Subovate to subcircular; rounded in front and sides, somewhat flattened posterolaterally. Broadest posteriorly (Twitchell, 1915; Cooke, 1953).
Top domed: Upper surface low convex; somewhat flattened on top; arched above the periproct (Twitchell, 1915; Cooke, 1953).
SIDE: Ambitus: Sides declining about equally to the margin; margin rounded on sides and anteriorly, somewhat angular at rostrated posterior end (Twitchell, 1915).
BOTTOM: Bottom shape: Gently concave centrally (Twitchell, 1915; Cooke, 1953).
AMB: Amb shape: Petals lanceolate; rather broad in petaloid dorsal portions (Twitchell, 1915).
Amb arrangement: Petals extend about three-fourths the way to the margin (Cooke, 1953).
Amb primary zones: Poriferous zones broad; closed at the apex, nearly closed distally (Cooke) vs. open at ends (Twitchell).
PORE PAIRS: Shape: Outer row slit-like or elongate; inner row round (Twitchell, 1915). Cooke (1953) describes outer pores as oval.
Conjugate vs Nonconjugate: Conjugate (Twitchell, 1915; Cooke, 1953).
TUBERCLES: Primary tubercles: Small scrobiculate tubercles cover the whole surface of the test (Twitchell, 1915).
APICAL SYSTEM: Location: Central or slightly in front of the center (Cooke, 1953); Excentric anteriorly (Twitchell, 1915).
Size: Small (Twitchell, 1915).
Genital pores: Four genital pores (Cooke, 1953).
Madreporite: Central (Cooke, 1953).
PERIPROCT (ANUS): Shape & Size: Small, round (Cooke, 1953).
Location: Supramarginal; about halfway between apical system and margin (Cooke, 1953).
Structure: Situated in a depression above the posterior rostration (Twitchell, 1915); at the upper end of a shallow groove that does not reach the margin (Cooke, 1953).
PERISTOME (MOUTH): Shape: Subpentagonal (Twitchell, 1915).
Location: Commonly a little behind the center (Cooke, 1953); Excentric anteriorly (Twitchell, 1915).
Lip: Bourrelets conspicuous, blunt, hollow (Cooke, 1953).
Phyllodes: Limited on each side by a curved line of about 11 close-set small pores; two inner nearly straight widely separated lines of about 6 pores. Not distinctly pitted; sloping steeply near the peristome (Cooke, 1953).
SPECIMENS STUDIED & CONDITION: Specimen USNM PAL 479792 (Type).
ETYMOLOGY
Named in honor of Ray S. Bassler (1878–1961), American paleontologist and curator at the U.S. National Museum (Twitchell, 1915).
REMARKS & COMPARISONS
Remarks: Twitchell (1915) originally described the oral features (floscelle) as "indistinct," but Cooke (1953) redefined the species with distinct, hollow bourrelets and specific phyllode counts.
Comparisons:
REMARK: Discrepancy in Peristome location (Twitchell = Anterior vs. Cooke = Posterior/Central). Cooke's description is generally considered the modern standard for this genus.
Plate: HaBa-10
Series: Upper Cretaceous Group: Taylor Formation: Anacacho Limestone
Locale: Muela Creek County: Kinney Stage: Campanian
Length: 24.3 mm Width: 22.7 mm Height: 10.7 mm
Specimen in photo: U.S.N.M. PAL479792 Type
Paleobiology Depart. NMNH, Smithsonian Institution
HOLOTYPE INFO:
Holotype: USNM 103863 (Twitchell, 1915) — National Museum of Natural History, Smithsonian Institution
Locality: Plymouth, North Carolina (Twitchell, 1915)
Stratigraphy: Eutaw Formation equivalents (Upper Cretaceous) (Cooke, 1953)
SYNONYMY
- Cassidulus bassleri Twitchell, 1915
SYSTEMATIC PALEONTOLOGY – TAXONOMY
Class: Echinoidea Leske, 1778
Subclass: Euechinoidea Bronn, 1860
Infraclass: Irregularia Latreille, 1825
Superorder: Neognathostomata Smith, 1981
Order: Cassiduloida Claus, 1880
Family: Faujasiidae Lambert, 1905
Genus: HARDOUINIA Haime, 1853
Species: Hardouinia bassleri (Twitchell, 1915)
TYPE SPECIES: Hardouinia potosiensis Lambert, 1911
DIAGNOSIS
Test small, subovate to subcircular, broadest posteriorly. Periproct supramarginal, situated in a depression above the posterior rostration. Petals lanceolate; bourrelets conspicuous, blunt, and hollow (Twitchell, 1915; Cooke, 1953).
STRATIGRAPHICAL OCCURRENCE & DISTRIBUTION
Group: Taylor
Formations: Anacacho Limestone (Texas); Eutaw/McShan equivalents (North Carolina)
Stratigraphic Units: Upper Cretaceous, Campanian
Counties: Kinney County (Texas)
DESCRIPTION
TOP: Length, width, height: 24.3 mm L × 22.7 mm W × 10.7 mm H
Top shape: Subovate to subcircular; rounded in front and sides, somewhat flattened posterolaterally. Broadest posteriorly (Twitchell, 1915; Cooke, 1953).
Top domed: Upper surface low convex; somewhat flattened on top; arched above the periproct (Twitchell, 1915; Cooke, 1953).
SIDE: Ambitus: Sides declining about equally to the margin; margin rounded on sides and anteriorly, somewhat angular at rostrated posterior end (Twitchell, 1915).
BOTTOM: Bottom shape: Gently concave centrally (Twitchell, 1915; Cooke, 1953).
AMB: Amb shape: Petals lanceolate; rather broad in petaloid dorsal portions (Twitchell, 1915).
Amb arrangement: Petals extend about three-fourths the way to the margin (Cooke, 1953).
Amb primary zones: Poriferous zones broad; closed at the apex, nearly closed distally (Cooke) vs. open at ends (Twitchell).
PORE PAIRS: Shape: Outer row slit-like or elongate; inner row round (Twitchell, 1915). Cooke (1953) describes outer pores as oval.
Conjugate vs Nonconjugate: Conjugate (Twitchell, 1915; Cooke, 1953).
TUBERCLES: Primary tubercles: Small scrobiculate tubercles cover the whole surface of the test (Twitchell, 1915).
APICAL SYSTEM: Location: Central or slightly in front of the center (Cooke, 1953); Excentric anteriorly (Twitchell, 1915).
Size: Small (Twitchell, 1915).
Genital pores: Four genital pores (Cooke, 1953).
Madreporite: Central (Cooke, 1953).
PERIPROCT (ANUS): Shape & Size: Small, round (Cooke, 1953).
Location: Supramarginal; about halfway between apical system and margin (Cooke, 1953).
Structure: Situated in a depression above the posterior rostration (Twitchell, 1915); at the upper end of a shallow groove that does not reach the margin (Cooke, 1953).
PERISTOME (MOUTH): Shape: Subpentagonal (Twitchell, 1915).
Location: Commonly a little behind the center (Cooke, 1953); Excentric anteriorly (Twitchell, 1915).
Lip: Bourrelets conspicuous, blunt, hollow (Cooke, 1953).
Phyllodes: Limited on each side by a curved line of about 11 close-set small pores; two inner nearly straight widely separated lines of about 6 pores. Not distinctly pitted; sloping steeply near the peristome (Cooke, 1953).
SPECIMENS STUDIED & CONDITION: Specimen USNM PAL 479792 (Type).
ETYMOLOGY
Named in honor of Ray S. Bassler (1878–1961), American paleontologist and curator at the U.S. National Museum (Twitchell, 1915).
REMARKS & COMPARISONS
Remarks: Twitchell (1915) originally described the oral features (floscelle) as "indistinct," but Cooke (1953) redefined the species with distinct, hollow bourrelets and specific phyllode counts.
Comparisons:
- Hardouinia mortonis: H. bassleri differs by having a supramarginal periproct located on the upper surface, whereas H. mortonis has a periproct located in a deep groove between the posterior petals.
- Hardouinia kellumi: H. bassleri is smaller and has a more central peristome.
REMARK: Discrepancy in Peristome location (Twitchell = Anterior vs. Cooke = Posterior/Central). Cooke's description is generally considered the modern standard for this genus.
