Hardouinia mortonis emmonsi (Stephenson, 1927)
Plate: HaMoEm-10
Series: Upper Cretaceous Group: Navarro Formation: Escondido
Locale: Indio Ranch County: Maverick Stage: Maastrichtian
Length: 24.3 mm Width: 22.8 mm Height: 10.7 mm
Specimen in photo: U.S.N.M. 464493
Paleobiology Depart. NMNH, Smithsonian Institution
HOLOTYPE INFO:
Holotype: USNM 73434 — National Museum of Natural History, Smithsonian Institution (Stephenson, 1927)
Locality: 2 miles east of Rocky Point, Pender County, North Carolina (Stephenson, 1927)
Stratigraphy: Peedee Formation (Stephenson, 1927)
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 mortonis (Michelin, 1851)
Subspecies: Hardouinia mortonis emmonsi (Stephenson, 1927)
TYPE SPECIES: Hardouinia potosiensis Lambert, 1911
DIAGNOSIS
Differs from typical Hardouinia mortonis in its smaller size and lower, more conical form (Cooke, 1953).
STRATIGRAPHICAL OCCURRENCE & DISTRIBUTION
Group: Navarro
Formations: Escondido Formation (Texas); Peedee Formation (North Carolina) (Cooke, 1953)
Stratigraphic Units: Upper Cretaceous, Maastrichtian (Exogyra costata zone) (Cooke, 1953)
Counties: Maverick County (Texas)
DESCRIPTION
TOP: Length, width, height: 24.3 mm L × 22.8 mm W × 10.7 mm H (Specimen); Avg Texas: 26 mm L x 24 mm W x 10.6 mm H (Cooke, 1953)
Top shape: Horizontal outline semi-circular in front, nearly straight posterolaterally, produced downward behind (Cooke, 1953).
Top domed: Upper surface variably inflated; emmonsi variety is lower and more conical than typical mortonis (Cooke, 1953).
SIDE: Ambitus: Margin angular to acutely rounded (Cooke, 1953).
BOTTOM: Bottom shape: Slightly concave (Cooke, 1953).
Callus: Bare callus-like area extends backward from the floscelle (Cooke, 1953).
AMB: Amb shape: Petaloid; petals lanceolate (Cooke, 1953).
Amb arrangement: Petals extend more than halfway to the ambitus (Cooke, 1953).
Amb primary zones: Poriferous zones closed at inner end, nearly closed and much wider at outer end (Cooke, 1953).
Phyllodes: Short, broad, depressed, very conspicuous (Cooke, 1953).
PORE PAIRS: Shape: Zygopores consist of a circular inner pore conjugated with a slot-shaped outer pore of variable length (Cooke, 1953).
TUBERCLES: Primary tubercles: Upper surface covered with small sunken tubercles. Lower surface covered with larger tubercles set at the outer edge of large semi-lunate scrobiculi, excluding the bare callus (Cooke, 1953).
APICAL SYSTEM: Location: Central (Cooke, 1953).
Genital pores: Four genital pores located beyond the inner ends of the petals (Cooke, 1953).
Madreporite: Large, central; extends between the posterior oculars (Cooke, 1953).
PERIPROCT (ANUS): Shape & Size: Small, circular (Cooke, 1953).
Location: Located between the ends of the posterior petals; sunken in a conical tube that widens into a straight-sided sulcus which extends to and slightly indents the ambitus (Cooke, 1953).
PERISTOME (MOUTH): Shape: Circular, tubular (Cooke, 1953).
Location: Central (Cooke, 1953).
Lip: Surrounded by five strong, pointed, hollow bourrelets covered with scale-like small tubercles and separated by deep pits (Cooke, 1953).
SPECIMENS STUDIED & CONDITION: Specimen USNM 464493 (Type Series) (Cooke, 1953).
ETYMOLOGY
Named in honor of Ebenezer Emmons (1799–1863), an American geologist who named the Taconic system and served as State Geologist of North Carolina (Stephenson, 1927).
REMARKS & COMPARISONS
Remarks: Specimens from Texas are uniformly smaller than the types of H. emmonsi from North Carolina. Cooke (1953) notes that Hardouinia mortonis shows considerable variation in shape, ranging from the conical H. subconicus to the lower H. emmonsi.
Comparisons:
Plate: HaMoEm-10
Series: Upper Cretaceous Group: Navarro Formation: Escondido
Locale: Indio Ranch County: Maverick Stage: Maastrichtian
Length: 24.3 mm Width: 22.8 mm Height: 10.7 mm
Specimen in photo: U.S.N.M. 464493
Paleobiology Depart. NMNH, Smithsonian Institution
HOLOTYPE INFO:
Holotype: USNM 73434 — National Museum of Natural History, Smithsonian Institution (Stephenson, 1927)
Locality: 2 miles east of Rocky Point, Pender County, North Carolina (Stephenson, 1927)
Stratigraphy: Peedee Formation (Stephenson, 1927)
SYNONYMY
- Cassidulus emmonsi Stephenson, 1927
- Hardouinia emmonsi (Stephenson, 1927)
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 mortonis (Michelin, 1851)
Subspecies: Hardouinia mortonis emmonsi (Stephenson, 1927)
TYPE SPECIES: Hardouinia potosiensis Lambert, 1911
DIAGNOSIS
Differs from typical Hardouinia mortonis in its smaller size and lower, more conical form (Cooke, 1953).
STRATIGRAPHICAL OCCURRENCE & DISTRIBUTION
Group: Navarro
Formations: Escondido Formation (Texas); Peedee Formation (North Carolina) (Cooke, 1953)
Stratigraphic Units: Upper Cretaceous, Maastrichtian (Exogyra costata zone) (Cooke, 1953)
Counties: Maverick County (Texas)
DESCRIPTION
TOP: Length, width, height: 24.3 mm L × 22.8 mm W × 10.7 mm H (Specimen); Avg Texas: 26 mm L x 24 mm W x 10.6 mm H (Cooke, 1953)
Top shape: Horizontal outline semi-circular in front, nearly straight posterolaterally, produced downward behind (Cooke, 1953).
Top domed: Upper surface variably inflated; emmonsi variety is lower and more conical than typical mortonis (Cooke, 1953).
SIDE: Ambitus: Margin angular to acutely rounded (Cooke, 1953).
BOTTOM: Bottom shape: Slightly concave (Cooke, 1953).
Callus: Bare callus-like area extends backward from the floscelle (Cooke, 1953).
AMB: Amb shape: Petaloid; petals lanceolate (Cooke, 1953).
Amb arrangement: Petals extend more than halfway to the ambitus (Cooke, 1953).
Amb primary zones: Poriferous zones closed at inner end, nearly closed and much wider at outer end (Cooke, 1953).
Phyllodes: Short, broad, depressed, very conspicuous (Cooke, 1953).
PORE PAIRS: Shape: Zygopores consist of a circular inner pore conjugated with a slot-shaped outer pore of variable length (Cooke, 1953).
TUBERCLES: Primary tubercles: Upper surface covered with small sunken tubercles. Lower surface covered with larger tubercles set at the outer edge of large semi-lunate scrobiculi, excluding the bare callus (Cooke, 1953).
APICAL SYSTEM: Location: Central (Cooke, 1953).
Genital pores: Four genital pores located beyond the inner ends of the petals (Cooke, 1953).
Madreporite: Large, central; extends between the posterior oculars (Cooke, 1953).
PERIPROCT (ANUS): Shape & Size: Small, circular (Cooke, 1953).
Location: Located between the ends of the posterior petals; sunken in a conical tube that widens into a straight-sided sulcus which extends to and slightly indents the ambitus (Cooke, 1953).
PERISTOME (MOUTH): Shape: Circular, tubular (Cooke, 1953).
Location: Central (Cooke, 1953).
Lip: Surrounded by five strong, pointed, hollow bourrelets covered with scale-like small tubercles and separated by deep pits (Cooke, 1953).
SPECIMENS STUDIED & CONDITION: Specimen USNM 464493 (Type Series) (Cooke, 1953).
ETYMOLOGY
Named in honor of Ebenezer Emmons (1799–1863), an American geologist who named the Taconic system and served as State Geologist of North Carolina (Stephenson, 1927).
REMARKS & COMPARISONS
Remarks: Specimens from Texas are uniformly smaller than the types of H. emmonsi from North Carolina. Cooke (1953) notes that Hardouinia mortonis shows considerable variation in shape, ranging from the conical H. subconicus to the lower H. emmonsi.
Comparisons:
- Hardouinia mortonis (Typical): Larger and higher than the emmonsi variety.
