Fibularia texana (Twitchell, 1915)
Plate: FiTe-10
Series: Eocene Group: Jackson Formation: Cook Mountain
Locale: San Augustine County: San Augustine Stage: Bartonian
Length: 6.1 mm Width: 5.1 mm Height: 4.9 mm
Specimens in photos: NPL 83002 (Hypotype)
Repository: Non-vertebrate Paleo. Lab., Univ. of Texas
HOLOTYPE INFO:
Holotype: USNM 559480 (Twitchell, 1915) — National Museum of Natural History, Smithsonian Institution (Zachos, 1990)
Locality: Elm Creek, Lee County, Texas (Designated by Zachos, 1990; originally "Lee County")
Stratigraphy: Cook Mountain Formation (Zachos, 1990)
SYNONYMY
SYSTEMATIC PALEONTOLOGY – TAXONOMY
Class: Echinoidea Leske, 1778
Subclass: Euechinoidea Bronn, 1860
Infraclass: Irregularia Latreille, 1825
Superorder: Neognathostomata Smith, 1981
Order: Clypeasteroida A. Agassiz, 1872
Suborder: Scutellina Haeckel, 1896
Family: Fibulariidae Gray, 1855
Genus: FIBULARIA Lamarck, 1816
Species: Fibularia texana (Twitchell, 1915)
TYPE SPECIES: Fibularia ovulum Lamarck, 1816
STRATIGRAPHICAL OCCURRENCE & DISTRIBUTION
Group: Claiborne
Formations: Weches Formation ; Cook Mountain Formation (Zachos & Molineux, 2003)
Stratigraphic Units: Middle Eocene, Bartonian/Lutetian
Counties: San Augustine ; Lee, Houston (Zachos & Molineux, 2003)
DESCRIPTION
TOP: Length, width, height: 6.1 mm L × 5.1 mm W × 4.9 mm H ; Holotype 5.1 mm L (Zachos, 1990)
Top shape: Horizontal outline oval (Cooke, 1942); Oblate to nearly spherical (Zachos & Molineux, 2003)
Top domed: Upper surface inflated (Cooke, 1942)
SIDE: Ambitus: Margin broadly rounded (Cooke, 1942)
BOTTOM: Bottom shape: Lower surface inflated (Cooke, 1942)
AMB: Amb shape: Petals long (Cooke, 1942)
Amb width: Poriferous zones straight, far apart, expanding, wide open distally (Cooke, 1942)
TUBERCLES: Primary tubercles: Sunken, close together (Cooke, 1942)
APICAL SYSTEM: Location: Central (Cooke, 1942)
Genital pores: Four genital pores, close together (Cooke, 1942)
PERIPROCT (ANUS): Shape & Size: Small, circular (Cooke, 1942)
Location: Nearer the peristome than the margin (Cooke, 1942)
PERISTOME (MOUTH): Size: Rather small (Cooke, 1942)
Shape: Circular (Cooke, 1942)
Location: Central (Cooke, 1942)
SPECIMENS STUDIED & CONDITION: Hypotype NPL 83002 studied .
ETYMOLOGY: Named for the state of Texas.
REMARKS & COMPARISONS
Comparisons:
Plate: FiTe-10
Series: Eocene Group: Jackson Formation: Cook Mountain
Locale: San Augustine County: San Augustine Stage: Bartonian
Length: 6.1 mm Width: 5.1 mm Height: 4.9 mm
Specimens in photos: NPL 83002 (Hypotype)
Repository: Non-vertebrate Paleo. Lab., Univ. of Texas
HOLOTYPE INFO:
Holotype: USNM 559480 (Twitchell, 1915) — National Museum of Natural History, Smithsonian Institution (Zachos, 1990)
Locality: Elm Creek, Lee County, Texas (Designated by Zachos, 1990; originally "Lee County")
Stratigraphy: Cook Mountain Formation (Zachos, 1990)
SYNONYMY
- Echinocyamus texanus Twitchell, 1915
- Fibularia meyeri (Aldrich, 1921)
- Fibularia alabamensis Cooke, 1959
SYSTEMATIC PALEONTOLOGY – TAXONOMY
Class: Echinoidea Leske, 1778
Subclass: Euechinoidea Bronn, 1860
Infraclass: Irregularia Latreille, 1825
Superorder: Neognathostomata Smith, 1981
Order: Clypeasteroida A. Agassiz, 1872
Suborder: Scutellina Haeckel, 1896
Family: Fibulariidae Gray, 1855
Genus: FIBULARIA Lamarck, 1816
Species: Fibularia texana (Twitchell, 1915)
TYPE SPECIES: Fibularia ovulum Lamarck, 1816
STRATIGRAPHICAL OCCURRENCE & DISTRIBUTION
Group: Claiborne
Formations: Weches Formation ; Cook Mountain Formation (Zachos & Molineux, 2003)
Stratigraphic Units: Middle Eocene, Bartonian/Lutetian
Counties: San Augustine ; Lee, Houston (Zachos & Molineux, 2003)
DESCRIPTION
TOP: Length, width, height: 6.1 mm L × 5.1 mm W × 4.9 mm H ; Holotype 5.1 mm L (Zachos, 1990)
Top shape: Horizontal outline oval (Cooke, 1942); Oblate to nearly spherical (Zachos & Molineux, 2003)
Top domed: Upper surface inflated (Cooke, 1942)
SIDE: Ambitus: Margin broadly rounded (Cooke, 1942)
BOTTOM: Bottom shape: Lower surface inflated (Cooke, 1942)
AMB: Amb shape: Petals long (Cooke, 1942)
Amb width: Poriferous zones straight, far apart, expanding, wide open distally (Cooke, 1942)
TUBERCLES: Primary tubercles: Sunken, close together (Cooke, 1942)
APICAL SYSTEM: Location: Central (Cooke, 1942)
Genital pores: Four genital pores, close together (Cooke, 1942)
PERIPROCT (ANUS): Shape & Size: Small, circular (Cooke, 1942)
Location: Nearer the peristome than the margin (Cooke, 1942)
PERISTOME (MOUTH): Size: Rather small (Cooke, 1942)
Shape: Circular (Cooke, 1942)
Location: Central (Cooke, 1942)
SPECIMENS STUDIED & CONDITION: Hypotype NPL 83002 studied .
ETYMOLOGY: Named for the state of Texas.
REMARKS & COMPARISONS
Comparisons:
- Fibularia vaughani: F. texana is less elongated, has genital plates closer together, and longer petals (Cooke, 1942).
- Fibularia alabamensis: F. texana has genital plates closer together and longer petals (Cooke, 1942). Note: Zachos & Molineux (2003) consider F. alabamensis a junior synonym of F. texana.
- Shape: Most specimens from the Weches (e.g., USGS 15093) are more highly inflated than the type (Cooke, 1942).
