Agraulos Hawle & Corda 1847
- 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
- Ptychopariida
- family
- Agraulidae
- genus
- Agraulos
diagnosis
DIAGNOSIS. — Cranidium parabolic and domed; exoskeleton thick; glabella domed, equal-sided to trapezoidal; preglabellar field long; thorax of 16 segments (based onLake 1932; Harrington et al. 1959; Fletcher 2017, with modifications).
discussion
REMARKS The genus was first described by Barrande (1846) as Arion. As the name Arion was occupied by a genus of gastropods, Hawle & Corda (1847) renamed the trilobite Arion to Agraulos. Barrande (1847) corrected his mistake and renamed the genus to Arionides. Barrande (1852 b) re-renamed the genus to Arionellus, as in his opinion Arionides might still be challenged by other authors. He rejected Agraulos Hawle & Corda (1847) as he found the name too similar to Agraulis, a genus of butterflies. Nevertheless, Pompeckj (1896) and Lake (1932) stated that a similarity of names, i. e. Agraulos and Agraulis, was not an adequate reason to reject the name given by Hawle & Corda (1947). Therefore, Agraulos is now the name established for this genus. Lake (1932) mentioned that Hawle & Corda (1847) described juvenile forms of Agraulos as the new genus Herse. The genus Agraulos is closely related to Skreiaspis Růžička, 1946, but differs by a longer preglabellar field (Harrington et al. 1959). Agraulos is here included in the family Agraulidae Howell, 1937, following e. g., Harrington et al. (1959), Martin & Dean (1988), Jell & Adrain (2002), Bentley & Jago (2004) and Weidner & Nielsen (2014). The limiting of Agraulidae to a subfamily of the family Solenopleuridae Angelin, 1854, as proposed by Fletcher (2017), is not followed herein. This latter author suggested that the same characters that support Agraulidae, as defined by Bentley & Jago (2004), are also seen in Parasolenopleura aculeata (Angelin, 1851), the reference species of the Solenopleuridae. However, the Solenopleuridae has a deep occipital furrow and a narrow border (Harrington et al. 1959), which differ from a weakly to effaced occipital furrow and presence of a preglabellar field, as characteristically seen in the Agraulidae (Harrington et al. 1959; Bentley & Jago 2004).
type_taxon
Type species: Arion ceticephalus Barrande, 1846, designated by Miller (1889).