Linthia hollandi Barry, 1942
Plate: LiHo-10
Series: Eocene Group: Wilcox Formation: Sabinetown
Locale: Pendleton County: Sabine Stage: Ypresian
Length: 18.4 mm Width: 18.0 mm (estimate) Height: 7.5 mm (estimate)
Specimen in photo: LSUMG #1-5058 Holotype
Collector: Not Specified
Repository: Museum of Natural Science, Louisiana State University
HOLOTYPE INFO:
Holotype: LSUMG 5058 (Barry, 1942).
Locality: Pendleton Bluff, Sabine County, Texas.
Stratigraphy: Sabinetown Formation, Wilcox Group.
SYSTEMATIC PALEONTOLOGY – TAXONOMY
Class: Echinoidea Leske, 1778
Subclass: Euechinoidea Bronn, 1860
Infraclass: Irregularia Latreille, 1825
Superorder: Atelostomata Zittel, 1879
Order: Spatangoida L. Agassiz, 1840
Family: Schizasteridae Lambert, 1905
Genus: LINTHIA Desor, 1853
Species: Linthia hollandi Barry, 1942
TYPE SPECIES: Linthia insignis (Merian, 1853)
DIAGNOSIS
Test small, cordate, and inflated; characterized by a deep anterior sulcus that notches the anterior margin. Petals are depressed and unequal; the peripetalous fasciole is distinct and deeply re-entrant between the petals (Barry, 1942).
STRATIGRAPHICAL OCCURRENCE & DISTRIBUTION
Group: Wilcox
Formations: Sabinetown Formation.
Stratigraphic Units: Paleogene, Eocene.
Counties: Sabine (Texas/Louisiana border region).
Abundance: Rare.
DESCRIPTION
TOP: Length, width, height: 18.4 mm L × ~18.0 mm W × ~7.5 mm H.
Top shape: Cordate; widest point is posterior of the midpoint. Deeply notched in front by the ambulacral sulcus.
Top domed: Very inflated; apex located at the apical system.
SIDE: Ambitus: Positioned near the adoral surface (low).
Side shape: Vertically truncated posteriorly (Barry, 1942).
BOTTOM: Bottom shape: Adoral surface convex (Barry, 1942). Holotype bottom is damaged.
AMB: Amb shape: Paired ambulacra are depressed and petaloid; petals are closed. The unpaired anterior ambulacrum is long, situated in a deep groove, and cuts deeply into the anterior margin.
Amb arrangement: Paired ambulacra are nearly equal in length. The anterior paired ambulacra are wider than the posterior pair (Barry, 1942). The posterior petals are more deeply depressed than the anterior pair.
PORE PAIRS: Arrangement: Biserial; slightly elongated and slightly oblique.
TUBERCLES: Distribution: Faint in the holotype specimen. Small and crowded on the plastron (Barry, 1942).
FASCIOLE: Peripetalous: Distinct and clearly marked; deeply re-entrant between the petals (Barry, 1942).
Latero-anal: A lateral fasciole is present (Barry, 1942).
APICAL SYSTEM: Location: Anterior of center.
Type: Ethmolytic; four genital pores (Barry, 1942).
PERIPROCT (ANUS): Shape: Oval (longitudinally).
Location: Located high on the posterior truncation (Barry, 1942); below the midpoint.
PERISTOME (MOUTH): Shape: Reniform (kidney-shaped).
Location: Anterior; located about 20% of the length of the test from the anterior end.
Lip: Labrum well developed (Barry, 1942).
SPINES: Unknown.
SPECIMENS STUDIED & CONDITION: Holotype LSUMG 5058. The specimen is damaged on the bottom and left side.
ETYMOLOGY
Named for Wilbur Holland, who assisted in the preparation of the paleontological report (Barry, 1942).
REMARKS & COMPARISONS
Remarks: This species was described by J.O. Barry in 1942 as part of a study on Eocene Spatangoids from Louisiana and the Texas border.
Comparisons:
Plate: LiHo-10
Series: Eocene Group: Wilcox Formation: Sabinetown
Locale: Pendleton County: Sabine Stage: Ypresian
Length: 18.4 mm Width: 18.0 mm (estimate) Height: 7.5 mm (estimate)
Specimen in photo: LSUMG #1-5058 Holotype
Collector: Not Specified
Repository: Museum of Natural Science, Louisiana State University
HOLOTYPE INFO:
Holotype: LSUMG 5058 (Barry, 1942).
Locality: Pendleton Bluff, Sabine County, Texas.
Stratigraphy: Sabinetown Formation, Wilcox Group.
SYSTEMATIC PALEONTOLOGY – TAXONOMY
Class: Echinoidea Leske, 1778
Subclass: Euechinoidea Bronn, 1860
Infraclass: Irregularia Latreille, 1825
Superorder: Atelostomata Zittel, 1879
Order: Spatangoida L. Agassiz, 1840
Family: Schizasteridae Lambert, 1905
Genus: LINTHIA Desor, 1853
Species: Linthia hollandi Barry, 1942
TYPE SPECIES: Linthia insignis (Merian, 1853)
DIAGNOSIS
Test small, cordate, and inflated; characterized by a deep anterior sulcus that notches the anterior margin. Petals are depressed and unequal; the peripetalous fasciole is distinct and deeply re-entrant between the petals (Barry, 1942).
STRATIGRAPHICAL OCCURRENCE & DISTRIBUTION
Group: Wilcox
Formations: Sabinetown Formation.
Stratigraphic Units: Paleogene, Eocene.
Counties: Sabine (Texas/Louisiana border region).
Abundance: Rare.
DESCRIPTION
TOP: Length, width, height: 18.4 mm L × ~18.0 mm W × ~7.5 mm H.
Top shape: Cordate; widest point is posterior of the midpoint. Deeply notched in front by the ambulacral sulcus.
Top domed: Very inflated; apex located at the apical system.
SIDE: Ambitus: Positioned near the adoral surface (low).
Side shape: Vertically truncated posteriorly (Barry, 1942).
BOTTOM: Bottom shape: Adoral surface convex (Barry, 1942). Holotype bottom is damaged.
AMB: Amb shape: Paired ambulacra are depressed and petaloid; petals are closed. The unpaired anterior ambulacrum is long, situated in a deep groove, and cuts deeply into the anterior margin.
Amb arrangement: Paired ambulacra are nearly equal in length. The anterior paired ambulacra are wider than the posterior pair (Barry, 1942). The posterior petals are more deeply depressed than the anterior pair.
PORE PAIRS: Arrangement: Biserial; slightly elongated and slightly oblique.
TUBERCLES: Distribution: Faint in the holotype specimen. Small and crowded on the plastron (Barry, 1942).
FASCIOLE: Peripetalous: Distinct and clearly marked; deeply re-entrant between the petals (Barry, 1942).
Latero-anal: A lateral fasciole is present (Barry, 1942).
APICAL SYSTEM: Location: Anterior of center.
Type: Ethmolytic; four genital pores (Barry, 1942).
PERIPROCT (ANUS): Shape: Oval (longitudinally).
Location: Located high on the posterior truncation (Barry, 1942); below the midpoint.
PERISTOME (MOUTH): Shape: Reniform (kidney-shaped).
Location: Anterior; located about 20% of the length of the test from the anterior end.
Lip: Labrum well developed (Barry, 1942).
SPINES: Unknown.
SPECIMENS STUDIED & CONDITION: Holotype LSUMG 5058. The specimen is damaged on the bottom and left side.
ETYMOLOGY
Named for Wilbur Holland, who assisted in the preparation of the paleontological report (Barry, 1942).
REMARKS & COMPARISONS
Remarks: This species was described by J.O. Barry in 1942 as part of a study on Eocene Spatangoids from Louisiana and the Texas border.
Comparisons:
- Linthia variabilis: L. hollandi differs by having a more deeply notched anterior margin and deeply depressed petals (Barry, 1942).
