Clarella Howell 1933
- Dataset
- Biostratigraphy and taxonomy of polymerid trilobites of the Manuels River Formation (Drumian, middle Cambrian), Newfoundland, Canada
- Rank
- GENUS
Classification
- kingdom
- Animalia
- phylum
- Arthropoda
- class
- Trilobita
- order
- Redlichiida
- family
- Centropleuridae
- genus
- Clarella
diagnosis
DIAGNOSIS. — Glabella with great forward expansion anterior of S 1; palpebral lobes slightly sigmoidal, reaching almost genal angle; thorax with 15 segments; pygidium without border, up to four pairs of marginal spines; short axis with one to two axial rings (based on Howell 1933; Whittington et al. 1997, with modifications).
discussion
REMARKS Clarella is distinguished from Anapolenus Salter, 1864 a by sigmoidally shaped palpebral lobes that almost reach the genal angle. The palpebral lobes of Anapolenus curve in a uniform arc, reaching the genal angle. The pygidium of Clarella lacks a border, while that of Anapolenus is bordered (Howell 1933; Whittington et al. 1997).
type_taxon
Type species: Anapolenus venustus Billings, 1872, designated as lectotype by Howell (1933).
Name
- Homonyms
- Clarella Howell 1933