Angelina (trilobite)

Angelina; Temporal range: Early Ordovician
	Angelina sedgwickii Salter, 1859. Coin diameter = 23.4mm.
Scientific classification
Kingdom:	Animalia
Phylum:	Arthropoda
Class:	Trilobita
Order:	Ptychopariida
Suborder:	Olenina
Family:	Olenidae
Subfamily:	Triarthrinae
Genus:	Angelina; Salter, 1859
Species
	A. sedgwickii Salter, 1859 (Type) ; A. hyeronimi ; A. kayseri ; A. punctolineata ; A. spinosa ;
Synonyms
	Keidelaspis

Angelina Salter, 1859, [1] is a genus of ptychopariid trilobite belonging to the Family Olenidae, Suborder olenina. It lived during the Tremadocian Stage, lowermost of the two standard worldwide divisions forming the Lower Ordovician Series and lowest of the seven stages within the Ordovician System. It encompasses all rocks formed during Tremadocian times, which spanned the interval between 485.4 million and 477.7 million years ago. Fossilized remains of Angelina are known from Wales, Central and South America. It differs from most other Triarthrinae in being larger, with a relatively narrow glabella, the occipital ring poorly defined, and lateral glabellar furrows relatively obscure. Eyes are placed midlength that of the cephalon and the facial sutures converge on the front border at the midline. Species also have long genal spines. [2]

The type species, Angelina sedgwickii Salter, 1859, was named for the Revd. Adam Sedgwick, the 19th Century Cambridge geologist who coined the term "Cambrian". This is the classic trilobite species found at Y Garth Hill, near Porthmadog, North West Wales (grid reference SH 598 394), and which has been collected for well over 100 years. This historic locality is described in Howells and Smith (1997) [3] and Rushton et al. (2000, p.111). [4] It lies in the Upper Mudstone Member of the Dol-cyn-afon Formation (formerly 'Angelina sedgwickii Beds' or 'Garth Hill Beds' of the Tremadoc slate.

Species

Angelina sedgwickii (Type species)
Angelina hyeronimi
Angelina kayseri
Angelina punctolineata
Angelina spinosa

Distribution

Fossils of Angelina have been found in Argentina, Bolivia, Mexico, [5] North West Wales and Shropshire, England.

Gallery

Angelina sedgwickii from the Tremadocian of North Wales.

References

SALTER, J. W., 1859. In Murchison, R. I., Siluria (3rd edition). John Murray, London. xix + 592 pp.
MOORE, R. C. (1959). Arthropoda I - Arthropoda General Features, Proarthropoda, Euarthropoda General Features, Trilobitomorpha. Treatise on Invertebrate Paleontology. Vol. Part O. Boulder, Colorado/Lawrence, Kansas: Geological Society of America/University of Kansas Press. pp. 1–560. ISBN 0-8137-3015-5.
HOWELLS, M. F. and SMITH M. 1997. The geology of the country around Snowdon. Memoir of the British Geological Survey, Sheet 119 (England and Wales) x + 104 pp.
RUSHTON, A. W. A., OWEN, A. W., OWENS R. M. and PRIGMORE J. K. 2000. Cambrian to Ordovician stratigraphy Joint Nature Conservation Council Peterborough, xxi + 435 pp. [dated 1999].
Angelina at Fossilworks.org

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[1] SALTER, J. W., 1859. In Murchison, R. I., Siluria (3rd edition). John Murray, London. xix + 592 pp.

[Treatise-2] MOORE, R. C. (1959). Arthropoda I - Arthropoda General Features, Proarthropoda, Euarthropoda General Features, Trilobitomorpha. Treatise on Invertebrate Paleontology. Vol. Part O. Boulder, Colorado/Lawrence, Kansas: Geological Society of America/University of Kansas Press. pp. 1–560. ISBN 0-8137-3015-5.

[3] HOWELLS, M. F. and SMITH M. 1997. The geology of the country around Snowdon. Memoir of the British Geological Survey, Sheet 119 (England and Wales) x + 104 pp.

[4] RUSHTON, A. W. A., OWEN, A. W., OWENS R. M. and PRIGMORE J. K. 2000. Cambrian to Ordovician stratigraphy Joint Nature Conservation Council Peterborough, xxi + 435 pp. [dated 1999].

[FWAngelina-5] Angelina at Fossilworks.org