Juvenile phacopid trilobites from the Prague Basin (Czech Republic)
Tóm tắt
Complete early ontogenetic stages of phacopid trilobites are very rare in the fossil record worldwide. Although phacopid trilobites were a common component of the Devonian communities inhabiting the Prague Basin, only two articulated juvenile individuals have been described so far. However, rich and diverse fauna, including common remains of meraspid and young holaspid specimens of the phacopid Pedinopariops superstes superstes, has been found in the late Emsian Daleje Shale (Daleje-Třebotov Formation) at the Čeřinka Quarry near Bubovice. The rather unusual association of skeletal fauna in the Daleje Shale collected from the Čeřinka Quarry probably reflects the specific position of the locality, which corresponds to the transition from shale facies to carbonate facies. This newly described association contains common molted young holaspids, one entire meraspid specimen, and one poorly preserved but entire late meraspid–early holaspid specimen. The young individuals of P. superstes superstes strongly resemble the ancestral Pedinopariops degener; with the exception of their smaller eyes, they are somewhat reminiscent of the coarsely tuberculated descendent Pedinopariops superstes superior. The principal differences between the early stages of P. superstes superstes and the adult specimens include the relatively coarse tuberculation of the dorsal exoskeleton, which is more strongly vaulted and shows a less advanced level of eye development in young specimens. However, co-occurring adult specimens appear to be typical P. superstes. Here, the newly collected material is supplemented with a description of two as yet unreported remains of juvenile Pedinopariops superstes from other localities, and one well preserved specimen of an entire meraspid of Reedops cf. bronni, as well as a detailed discussion of the two previously described specimens of Pedinopariops insequens and Prokops hoeninghausi. Possible causes of an obvious paucity of articulated meraspid and young holaspid specimens when compared with adult and subadult ontogenetic stages in phacopid trilobites are discussed.
Tài liệu tham khảo
Alberti, H. 1972. Ontogenie des Trilobiten Phacops accipitrinus. Neues Jahrbuch für Mineralogie, Geologie und Paläontologie, Abhandlungen 141(1): 1–36.
Barrande, J. 1846. Notice préliminaire sur le système Silurien et les trilobites de Bohême. vi+ 1–97. Leipzig.
Barrande, J. 1852. Systême Silurien du centre de la Bohême. lère partie. Recherches paléontologiques, vol. I. Crustacès, Trilobites, xxx+ 935 pp. Prague and Paris.
Budil, P., F. Hörbinger, and R. Mencl. 2009. Lower Devonian dalmanitid trilobites of the Prague Basin (Czech Republic). Earth and Environmental Science Transactions of the Royal Society of Edinburgh, Earth Sciences 99(2): 61–100. doi:10.1017/S1755691009006161.
Chlupáč, I. 1971. New phacopid trilobites from the Devonian of Czechoslovakia. Časopis pro mineralogii a geologii 16(3): 255–261.
Chlupáč, I. 1977. The phacopid trilobites of the Silurian and Devonian of Czechoslovakia. Rozpravy Ústředního ústavu geologického 43: 1–164.
Chlupáč, I. and Z. Kukal. 1986. Reflection of possible global Devonian events in the Barrandian area, ČSSR. Lecture Notes in Earth Sciences, Global Bio-Events 8: 169–179.
Chlupáč, I., V. Havlíček, J. Kříž, Z. Kukal, and P. Štorch. 1998. Palaeozoic of the Barrandian (Cambrian to Devonian). Czech Geological Survey, 183 pp, Prague.
Crônier, C. 2007. Larval morphology and ontogeny of an Upper Devonian phacopid: Nephranops from Thuringia, Germany. Journal of Paleontology 81(4): 684–700. doi:10.1666/pleo0022-3360(2007)081[0684:LMAOOA]2.0.CO;2.
Crônier, C. 2010. Varied development of trunk segmentation in three related Upper Devonian phacopine trilobites. Historical Biology 22(4): 341–347. doi:10.1080/08912960903548712.
Crônier, C., and R. Feist. 1997. Morphologie et évolution ontogenétique de Trimerocephalus lelievrei nov. sp., premier trilobite phacopidé aveugle du Famennien nord-africain. Géobios Mémoire Spécial 20: 161–170. doi:10.1016/S0016-6995(97)80021-6.
Crônier, C., and R.A. Fortey. 2006. Morphology and ontogeny of an Early Devonian phacopid trilobite with reduced sight from southern Thailand. Journal of Paleontology 80(3): 529–536. doi:10.1666/0022-3360(2006)80[529:MAOOAE]2.0.CO;2.
Crônier, C., S. Renaud, R. Feist, and J.C. Auffray. 1998. Ontogeny of Trimerocephalus lelievrei (Trilobita Phacopida) a representative of the Late Devonian phacopine paedomorphocline: A morphometric approach. Paleobiology 24(3): 359–370.
Crônier, C., K. Bartzsch, D. Weyer, and R. Feist. 1999. Larval morphology and ontogeny of a Late Devonian phacopid with reduced sight from Thuringia, Germany. Journal of Paleontology 73(2): 240–255.
Crônier, C., A. Bignon, and A. Francois. 2011. Morphological and ontogenetic criteria for defining a trilobite species: The example of Siluro-Devonian Phacopidae. Comptes Rendus Palevol 10(2–3): 143–153. doi:10.1016/j.crpv.2010.10.003.
Feist, R., K.J. McNamara, C. Crônier, and R. Lerosey-Aubril. 2009. Patterns of extinction and recovery of phacopid trilobites during the Frasnian-Famennian (Late Devonian) mass extinction event, Canning Basin, Western Australia. Geological Magazine 146(1): 12–33. doi:10.1017/S0016756808005335.
Ferrová, L., J. Frýda, and P. Lukeš. 2012. High-resolution tentaculite biostratigraphy and facies development across the Early Devonian Daleje Event in carbonate dominated environments of Barrandian (Bohemia). Bulletin of Geosciences 87(3): 587–624. doi:10.3140/bull.geosci.1336.
Hawle, J., and A.J.C. Corda. 1847. Prodrom einer monographie der böhmischen Trilobiten. Abhandlungen der Königlichen Böhmischen Gesellschaft der Wissenschaften: 1–176, Prague (J.G. Calve).
Horný, R., and F. Bastl. 1970. Type specimens of fossils in the National Museum Prague, I. Trilobita. Přírodovědecké Muzeum, 1–356 pp., Prague.
Kácha, P., and V. Petr. (1996). Camouflage and mimicry in fossils I: general part. Acta Musei Nationalis Pragae, Ser. B., Historia Naturalium 51(1–4): 53–82.
McKellar, R.C., and B.D.E. Chatterton. 2009. Early and Middle Devonian Phacopidae (Trilobita) of southern Morocco. Palaeontographica Canadiana 28: 1–110.
Osmólska, H. 1963. On some Famennian Phacopinae from the Holy Cross Mountains (Poland). Acta Palaeontologica Polonica 3(2): 119–148.
Owen, A.W. 1985. Trilobite abnormalities. Transactions of the Royal Society of Edinburgh 76(2–3): 255–272.
Struve, W. 1970. Beiträge zur Kenntnis der Phacopina (Trilobita) 7. Phacops-Arten aus dem Rheinischen Devon. 1. Senckenbergiana Lethaea 51(2–3): 133–189.
Struve, W. 1972. Beiträge zur Kenntnis der Phacopina (Trilobita). 8. Phacops-Arten aus dem rheinischen Devon. 2. Senckenbergiana Lethaea 53(5): 383–403.
Whittington, H.B., W.T. Chang, W.T. Dean, R.A. Fortey, P.A. Jell, J.R. Laurie, A.R. Palmer, L.N. Repina, A.W.A. Rushton, and J. Shergold. 1997. Morphological terms applied to Trilobita. In Treatise on invertebrate paleontology, part O (revised): Arthropoda 1: Trilobita, ed. R.C. Moore, and R.L. Kaesler, O331–O383. Lawrence/Kansas: Geological Society of America and University of Kansas Press.