Agraulos

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For the figures from Greek mythology, see Aglaurus. For the butterfly Agraulis vanillae, see Gulf fritillary.

Agraulos
Temporal range: Middle Cambrian
~510–499 Ma
Agraulos ceticephalus St Davids.jpg
Agraulos ceticephalus (Barrande, 1846), Menevia Formation, H. parvifrons Biozone, Porth-y-rhaw, St David's, Wales. Scale bar represents 1 mm.
Scientific classification
Kingdom:
Animalia
Phylum:
Arthropoda
Class:
Trilobita
Order:
Ptychopariida
Superfamily:
Ptychoparioidea
Family:
Solenopleuridae
Subfamily:
Genus:
Agraulos

Hawle & Corda, 1847
Species
  • A. ceticephalus (Barrande, 1846) = Arion ceticephalus, Arionides ceticephalus, Arionellus ceticephalus, Arionellus longicephalus.
  • A. socialis and A. affinis (Billings, 1872).
  • A. lewisi Fletcher, 2017.
Synonyms

Arion Barrande, 1846
non Arion Férussac, 1819
Arionides Barrande, 1847
Arionellus Barrande, 1850
Agrauloides Howell, 1937

Agraulos Hawle & Corda 1847,[1] is a genus of trilobites that lived during the Middle Cambrian in North America and Europe, particularly the Czech Republic.

Etymology[]

Agraulos is derived from the Greek Ἄγραυλος, "country woman", wife of Kekrops.[2]

Type species[]

Type species (designated by Miller 1889).[3] Arion ceticephalus Barrande, 1846 [4] from the Cambrian Eccaparadoxides pusillus Zone in the Skryje Member of the , within the Skryje–Tyrovice Basin, Bohemia.

Familial status[]

Family SOLENOPLEURIDAE (Angelin, 1854).[5]

Subfamily AGRAULINAE Fletcher, 2017 emend.[6] nom. transl. ex AGRAULIDAE Raymond. 1913.[7]

Diagnosis[]

Agraulinae with cephala generally domed; glabella isosceles-trapezoidal, i.e. with truncate front and base angles of the forward-converging lateral margins/flanks more than 15°; occipital ring mesially swollen backwards, with or without a medial node or spine; preglabellar field relatively long (sag.); posterolateral projection of fixigena narrow (tr.); librigenal spines short to long, with some deflected outwards. Thorax of up to 16 segments with first anterior axial rings marked by terrace lines immediately succeeded in some species by rings bearing incipient median nodes or incipient/prominent spines; thoracic segments finely punctate or granulate. Pygidium, small and transverse (Fletcher, 2017, pp, 9,10).

Distribution[]

  • A. ceticephalus (= Arionellus longicephalus Hicks, 1872) [8] occurs in the Middle Cambrian of the Czech Republic.[9] The species was first described from the Skryje Member of the Buchava Formation (Clupáč et al. 1998; Fatka et al. 2011) [10][11] on the slopes of the river Berounka in the Týřovice-Luh-Skryje area between Prague (Praha) and Pilsen (Plzen) in the Skryje-Týřovice Basin. The species has been recovered also from the of St. David's, South Wales (Fletcher, 2017, Fig. 8, I, J, K and Fig. 9, A-C) and, as its junior subjective synonym "Agraulos longicephalus" (Hicks, 1872), from the Nant-y-big Formation (Hypagnostus parvifrons Biozone) of Porth Ceiriad, North Wales (Young et al., 2002; Young et al., 1994, p. 343),[12][13] the Manuels river formation of Eastern Newfoundland (Martin and Dean, 1988, p. 21, pl.3, figs. 6-12),[14] and Spain (Sdzuy, 1961, pl.23, ?figs. 8-11, 15).[15] Fletcher (2017, p. 26) observed that specimens described by Weidner and Nielsen (2015, pl. 41A–F; Fig. 22B) as Agraulos longicephalus [16] (from the Middle Cambrian Paradoxides paradoxissimus Superzone of the Alum Shale Formation and within the lower and upper parts of the Ptychagnostus s.l. atavus Zone as well as in the Ptychagnostus punctuosus Zone), are in fact "marked by a conspicuous small median projection on the occipital ring, quite different from any species recorded elsewhere".
  • A. socialis (Billings, 1872) occurs in the Manuels River Formation (Drumian Stage) of Eastern Newfoundland where localities include the eastern side of chapel arm in Trinity Bay, Deep Cove in St Mary's Bay, and the Manuels River Section near St John's (Fletcher, 2017, p. 25). Fletcher also observed (op. cit. pp. 25, 26) that “of all the specimens referred to ‘longicephalus’, the exoskeleton from the Montagne Noire figured by Courtessole (1973, pl. 10, fig. 5; Fig. 22P) [17] appears to be very close to A. socialis, as are Sdzuy’s 1961 illustrations of associated Spanish cranidia and a thoracic axis without notable nodes or spines”.
  • A. affinis (Billings, 1872) derives from the Big Gulley Member green mudstone of the Chamberlain's Brook Formation in the coastal cliffs of the greater Branch Cove on both sides of the Branch River estuary, St Mary's Bay, Newfoundland, originally as part of the Geological Survey of Newfoundland Collection (Fletcher, op. cit, p. 21). The species occurs in association with the Scandinavian taxa Condylopyge carinata Westergärd, 1936 and [Solenopleura cristata Linnarsson, 1877] [18] indicating a zonal position about that of Ptychagnostus praecurrens (Fletcher, op.cit.) and Eccaparadoxides oelandicus.
  • A. lewisi, Fletcher, 2017 (p. 19, fig. 9D-I) [19] is recorded from the Menevia Formation of Porth-y-rhaw, St. David's, Wales and derives from the Hypagnostus parvifrons Biozone (Localities PR-4 and PR-16 of Rees et al., 2014).[20] The species is also recorded from the parvifrons Zone in the Harlech Dome of North Wales, , above Rhaiadr Bridge (Fletcher, op. cit. Fig. 8, F & G).

Remarks[]

Arionellus quadrangularis Whitfield (1884, p. 147, pl. 14, fig. 8), collected originally from the mid-Cambrian Braintree Formation at Old Hayward Quarry, Quincy, Massachusetts, USA, has previously been assigned to Agraulos by several authors, commencing with Walcott in 1884.[21] MacMenamin (2002), however, erected Skehanos gen. nov. to accommodate the species quadrangularis.[22]

Scandinavian species attributed by Westergård (1953) [23] to Agraulos [i.e. difformis, aculeatus, acuminatus (all Angelin, 1851), and anceps sp. nov.] were transferred by Ahlberg & Bergström (1978) [24] to Proampyx Frech 1897, [25] although several Lower Cambrian forms they also assigned to Proampyx would later be allocated to various other genera.

References[]

  1. ^ HAWLE, J. & CORDA, A. J. C. 1847. Prodrom einer Monographieder bohmischen Trilobiten. 176 pp. J. G. Calve, Prague
  2. ^ VANĚK, J.; VALIČEK, J.; VOKÁČ, V. (1999). "Plutonides hicksi (Salter) from the Middle Cambrian of Skryje - Týřovice Area (Czech Republic)" (PDF). Palaeontologica Bohemiae. 6: 36–38. Retrieved 2015-01-04.
  3. ^ MILLER, S. A. 1889. North American geology and palaeontology for the use of amateurs, students and scientists, 664 pp. Western Methodist Book Concern, Cincinnati, OH.
  4. ^ BARRANDE, J. 1846. Notice pre Âliminaire sur le syste Áme silurien et les trilobites de Bohême. Leipzig, 97 pp,
  5. ^ ANGELIN, N. P. (1854). Paleontologica Scandinavica. Pars 2. Crustacea formationis transitionis. Academiae Regiae Scientiorum Suecanae (Holmiae): I-IX + 21-92).
  6. ^ FLETCHER, TERENCE P. 2017. Agraulos ceticephalus and other Cambrian trilobites in the subfamily Agraulinae from Bohemia, Newfoundland and Wales. Papers in Palaeontology, pp.1-43, 22 figs.
  7. ^ RAYMOND, P. E. 1913. Some changes in the names of genera. Trilobites. Ottawa Naturalist, 26, 137–142.
  8. ^ HICKS, H. 1872. On some undescribed fossils from the Menevian Group with a note on the Entomostraca by Prof. T. Rupert Jones. Quarterly Journal of the Geological Society of London, 28, 173–185.
  9. ^ S.M. GON III. "Trilobites of the Jince Formation, Czech Republic". Retrieved 2015-01-04.
  10. ^ CHLUPÁČ, I., FATKA, O., PROKOP R. J., and TUREK V. 1998. Research of the classical palaeontological locality "Luh" in the Cambrian of Skryje (Barrandian area, Czech Republic). Journal of the Czech Geological Society. 43 (3), 169-174 (in Czech).
  11. ^ FATKA, O., MICKA, V., SZABAD, M., VOKÁČ V., VOREL T. 2011. Nomenclature of Cambrian lithostratigraphy of the Skryje-Týřovice Basin, Bulletin of Geosciences 86 (4): 841 - 85
  12. ^ YOUNG, T. P., GIBBONS, W., DEAN, W. T. and McCARROLL, D. 2002. Geology of the Country around Pwllheli. Memoir of the British Geological Survey, 1:50,000 Geological Sheet 134 (England and Wales). The Stationery Office, London
  13. ^ YOUNG, T. P., MARTIN, F., DEAN W. T. & RUSHTON, A. W. A. 1994. Cambrian stratigraphy of St Tudwal’s Peninsula, Gwynedd, northwest Wales, Geo!. Mag. 131 (3), 1994, pp. 335-360
  14. ^ MARTIN, F. and DEAN, W. T. 1988. Middle and Upper Cambrian acritarch and trilobite zonation at Manuels River and Random Island, Eastern Newfoundland. Geological Survey of Canada Bulletin, 381, 1-91
  15. ^ SDZUY, K. 1961. Das Kambrium Spaniens, Teil II: Trilobiten. Abhandlungen der Mathematisch-Naturwissenschaftlichen Klasse, 8, 597 – 693 [315 – 411]. Akademie der Wissenschaften und der Literatur, Mainz & Wiesbaden
  16. ^ WEIDER, T. & NIELSEN, A. T. 2015. Agraulos longicephalus and Proampyx? depressus (Trilobita) from the Middle Cambrian of Borggård, Øle on Bornholm, Denmark. Bulletin of the Geological Society of Denmark, Vol. 63, pp. 1–11
  17. ^ COURTESSOLE, R. 1973. Le Cambrien Moyen de la Montagne Noire, Biostratigraphie. Imprimerie d’ Oc, Toulouse, 248 pp)
  18. ^ LINNARSSON, J. G. O. 1877. Om faunan i lagren med Paradoxides Ölandicus. Geologiska Föreningens i Stockholm Förhandlingar, 3 (12), 352–375.
  19. ^ FLETCHER, TERENCE P. 2017. Agraulos ceticephalus and other Cambrian trilobites in the subfamily Agraulinae from Bohemia, Newfoundland and Wales. Papers in Palaeontology, pp.1-43, 22 figs.
  20. ^ REES, A. J., THOMAS, A. T., LEWIS, M., HUGHES, H. E. & TURNER, P. 2014. The Cambrian of SW Wales: Towards a United Avalonian Stratigraphy. Geological Society, London, Memoirs, 42, 1–30.
  21. ^ WALCOTT, C. D. 1884. On the Cambrian faunas of North America. Preliminary studies. United States Geological Survey Bulletin 10, 289-355
  22. ^ McMENAMIN, M. A. S. 2002. The ptychoparioid trilobite Skehanos gen. nov. from the Middle Cambrian of Avalonian Massachusetts and the Carolina Slate Belt, USA. Northeastern Geology & Environmental Sciences, 24 (4), 276 - 281.
  23. ^ WESTERGÅRD, A. H. 1953. Non-agnostidean trilobites of the Middle Cambrian of Sweden. III. Sveriges Geologiska Undersökning 526, 1 – 58.
  24. ^ AHLBERG, P. & BERGSTRÖM, J. 1978. Lower Cambrian Ptychopariid trilobites from Scandinavia. Sveriges Geologiska Undersökning Ca 49, 1 – 41.
  25. ^ FRECH, F. 1897, Lethaea geognostica oder Beschreibung und Abbildung der für die Gebirgs-Formationen bezeichnendsten Versteinerungen. I. Theil. Lethaea Palaeozoica. 2. Band. 788 pp. E. Schweizerbarth’sche Verlagshandlung, Stuttgart.
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