Haplophrentis

Haplophrentis
Temporal range: Middle Cambrian[1]
Reconstruction of Haplophrentis
Scientific classification
Kingdom: Animalia
Phylum: incertae sedis
Class: Hyolitha
Order: Hyolithida
Family: Hyolithidae
Genus: Haplophrentis
Species
  • H. carinatus Babcock & Robison 1988[1] (Matthew, 1899) (= H. cecrops Walcott)
  • H. reesei Babcock & Robison 1988 (type)
Haplophrentis carinatus from the Stephen Formation, Burgess Shale (Middle Cambrian), Burgess Pass, British Columbia, Canada.

Haplophrentis was a tiny shelled hyolithid which lived in the Cambrian Period. Its shell was long and conical, with the open end protected by an operculum, from which two fleshy arms called helens protruded at the sides. These arms probably acted as stabilisers, or were used for locomotion, rowing the animal across undersea mudflats.

Morphology

Haplophrentis ranged in length between 2–6 cm. It is distinguished from Hyolithes by the presence of a longitudinal septum on the middle of the inner surface of the top of the shell.[1]

Affinity

The hyolithids are thought to belong to the molluscan total-group, although this is uncertain.[2]

Ecology

Specimens of Haplophrentis have been found in the gut of the predator Ottoia.

Occurrence

186 specimens of Haplophrentis are known from the Greater Phyllopod bed, where they comprise 0.35% of the community.[3]

References

  1. 1 2 3 Babcock, L. E.; Robison, R. A. (1988). "Taxonomy and paleobiology of some Middle Cambrian Scenella (Cnidaria) and Hyolithids (Mollusca) from western North America" (PDF). University of Kansas Paleontological Contributions. 121: 1–22. hdl:1808/3638.
  2. Wotte, T (2006). "New Middle Cambrian molluscs from the Láncara Formation of the Cantabrian Mountains (north-western Spain)". Revista Española de Paleontología. 21 (2): 145–158.
  3. Caron, Jean-Bernard; Jackson, Donald A. (October 2006). "Taphonomy of the Greater Phyllopod Bed community, Burgess Shale". PALAIOS. 21 (5): 451–65. doi:10.2110/palo.2003.P05-070R. JSTOR 20173022.
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