Biology:Websteroprion

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Short description: Genus of annelid worms


Websteroprion
Temporal range: Late Emsian-Early Eifelian
~393.3 Ma
Photographs of Websteroprion armstrongi - Srep43061-f1.jpg
Scientific classification edit
Domain: Eukaryota
Kingdom: Animalia
Phylum: Annelida
Class: Polychaeta
Genus: Websteroprion
Eriksson et al., 2017[1]
Species:
W. armstrongi
Binomial name
Websteroprion armstrongi
Eriksson et al., 2017[1]

Websteroprion ("Webster's saw") is a genus of eunicidan polychaete that lived during the middle Devonian period in what is now Canada . It contains a single species, W. armstrongi, recovered from the Kwataboahegan Formation.[1]

Etymology

The genus was named after the bassist Alex Webster of the death metal band Cannibal Corpse.[2] Websteroprion features first representative of an invertebrate taxon.[3]Websteroprion represents the oldest bobbit worm which is about 400 million years old and it is a giant bobbit worm.[4]

Description

Websteroprion is known from the maxillae of several individuals in one location. These maxillae reaching 1.32 cm (0.52 in) in length, with one incomplete specimen that supposed to be bigger in full size. These are the largest jaws of any fossil polychaete.[1] A larger fossil jaw had been reported in 1934[5] but that specimen is too undiagnostic so it regarded as a nomen dubium.[1] Referencing the jaw to body size ratio of other polychaetes, Websteroprion could have grown to 1–2 m (3 ft 3 in–6 ft 7 in) long, though the exact size is unknown without soft tissue preservation.[1]

The maxillae of Websteroprion are denticulate (having teeth-like structures), while those of extant eunicids and onuphids are not. However, larvae of these two modern families do have deticulated maxillae, possibly strengthening an ancestral connection between the groups.[1]

No mandibles were found alongside the maxillae at the site of discovery, which leads to the possibility that these structures could not be preserved or that the maxillae were shed by Websteroprion while their mandibles were not.[1]

Paleoecology

The feeding practices of Websteroprion, though unknown, may be similar to the modern day Eunice aphroditois due to similarities in jaw structure. If this is true, Websteroprion would use its large jaws to eat live prey, algae, and decaying matter. However, the jaws of polychaetes do not necessarily designate specific feeding habits, so precise knowledge remains unknown without preserved gut content or soft tissue.[1]

All of the specimens of Websteroprion are of a similar large size, which may indicate juveniles and adults had differing environmental preferences and thus would not be preserved together. Though juvenile specimens may have simply not been preserved.[1]

The large size of Websteroprion is unique compared to other Devonian polychaetes, and the specific driving mechanisms for the increased size, whether intrinsic or extrinsic, are unknown.[1]

References

  1. 1.00 1.01 1.02 1.03 1.04 1.05 1.06 1.07 1.08 1.09 1.10 Eriksson, Mats E.; Parry, Luke A.; Rudkin, David M. (February 2017). "Earth's oldest 'Bobbit worm' – gigantism in a Devonian eunicidan polychaete" (in en). Scientific Reports 7 (2): 239–260. doi:10.1038/srep43061. PMID 28220886. 
  2. Mortillaro, Nicole (Feb 24, 2017). "New species of gigantic, toothy worm identified in Canadian fossil collection". https://www.cbc.ca/news/science/400-million-year-old-gigantic-worm-1.3996315. 
  3. Richter, Martha; Neis, Pedro Alfredo; Smith, Moya Meredith (1999-11-24). "Acanthodian and Actinopterygian fish remains from the Itaituba Formation, Late Carboniferous of the Amazon Basin, Brazil, with a note on acanthodian ganoin". Neues Jahrbuch für Geologie und Paläontologie - Monatshefte 1999 (12): 728–744. doi:10.1127/njgpm/1999/1999/728. ISSN 0028-3630. http://dx.doi.org/10.1127/njgpm/1999/1999/728. 
  4. Richter, Martha; Neis, Pedro Alfredo; Smith, Moya Meredith (1999-11-24). "Acanthodian and Actinopterygian fish remains from the Itaituba Formation, Late Carboniferous of the Amazon Basin, Brazil, with a note on acanthodian ganoin". Neues Jahrbuch für Geologie und Paläontologie - Monatshefte 1999 (12): 728–744. doi:10.1127/njgpm/1999/1999/728. ISSN 0028-3630. http://dx.doi.org/10.1127/njgpm/1999/1999/728. 
  5. Eller E. R. Annelid jaws from the Hamilton group of Ontario County, New York. Ann. Carnegie Mus. 24, 51–56 (1934).

Wikidata ☰ Q31837657 entry