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Patterns of extinction and recovery of phacopid trilobites during the Frasnian–Famennian (Late Devonian) mass extinction event, Canning Basin, Western Australia


A diverse fauna of phacopid trilobites is described from the Late Devonian (middle Frasnian to early Famennian) of the northern Canning Basin, Western Australia. One new genus and four species in two genera are described from zones 11, 13a and 13b of the middle and late Frasnian: Trimerocephaloides sinevisus gen. nov. and sp. nov., T. ? linguiformis sp. nov., Acuticryphops acuticeps (Kayser, 1889) and A. klapperi sp. nov. Late Frasnian phacopines are either blind, as shown for the first time in Trimerocephaloides sinevisus, or show trends to decreasing eye size up to the Frasnian–Famennian ‘Kellwasser’ mass extinction event. This evolutionary trend in Acuticryphops is demonstrated to have been global at this time. One new genus and six species of early Famennian phacopids are described, from the Upper triangularis, crepida and rhomboidea zones: Houseops gen. nov. with the new taxa H. canningensis sp. nov., H. beckeri sp. nov. and H. sp. A, Babinops planiventer Feist & Becker, 1997, B. minor sp. nov., Trimerocephalus tardispinosus Feist & Becker, 1997 and T. mimbi sp. nov. In contrast to European sections where exclusively blind phacopids are known in earliest Famennian sites, initial recovery following the mass extinction event in Canning peri-reefal environments is characterized by oculated forms. These trilobites must have evolved from conservative ancestors with normal eyes that had succeeded in surviving the Kellwasser biocrises in reef-related shallow water niches. Thus the origin of post-event phacopids from shallow water environments is demonstrated for the first time. Descendant lineages show increasing eye size, increased cephalic vaulting and effacement during the early Famennian.

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G. K. B. Alberti 1970. Zur Augenreduktion bei devonischen Trilobiten, mit Beschreibung von Nephranops franconicus n.sp. aus dem Oberdevon Iα von Oberfranken. Paläontologische Zeitschrift 44 (3/4), 145–60.

R. T. Becker , M. R. House , W. T. Kirchgasser & P. E. Playford 1991. Sedimentary and faunal changes across the Frasnian/Famennian boundary in the Canning Basin of Western Australia. Historical Biology 5, 183–96.

C. Crônier 1999. Modalités d'évolution phylétique sous contrôle du milieu chez quelques phacopinés (trilobites) néodévoniens. Geobios 32, 187–92.

C. Crônier 2007. Larval morphology and ontogeny of an Upper Devonian phacopid: Nephranops from Thuringia, Germany. Journal of Paleontology 81, 684700.

C. Crônier , K. Bartzsch , D. Weyer & R. Feist 1999. Larval morphology and ontogeny of a Late Devonian phacopid with reduced sight from Thuringia, Germany. Journal of Paleontology 73, 240–55.

C. Crônier & R. Feist 2000. Evolution et systématique du groupe Cryphops (Phacopinae, Trilobita) du Dévonien supérieur. Senckenbergiana lethaea 79, 501–15.

C. Crônier , R. Feist & J.-C. Auffray 2004. Variation in the eye of Acuticryphops (Phacopina, Trilobita) and its evolutionary significance: a biometric and morphometric approach. Paleobiology 30, 471–81.

R. Feist 1991. The late Devonian trilobite crises. Historical Biology 5, 197214.

R. Feist & K. J. McNamara 2007. Biodiversity, distribution and patterns of extinction of the last odontopleuroid trilobites during the Devonian (Givetian, Frasnian). Geological Magazine 144, 777–96.

A. D. George & N. Chow 2002. The depositional record of the Frasnian/Famennian boundary interval in a fore-reef succession, Canning Basin, Western Australia. Palaeogeography, Palaeoclimatology, Palaeoecology 181, 347–74.

C. Girard , G. Klapper & R. Feist 2005. Subdivision of the terminal Frasnian linguiformis conodont Zone, revision of the correlative interval of Montagne Noire Zone 13, and discussion of stratigraphically significant associated trilobites. In Understanding Late Devonian and Permian–Triassic Biotic and Climatic Events: Towards an Integrated Approach (eds D. J. Over , J. R. Morrow & P. B. Wignall ), pp. 181–98. Amsterdam: Elsevier.

G. J. Holloway , R. M. Sibley & S. R. Povey 1990. Evolution in toxin-stressed environments. Functional Ecology 4, 289–94.

G. Klapper 2007. Frasnian (Upper Devonian) conodont succession at Horse Spring and correlative sections, Canning Basin, Western Australia. Journal of Paleontology 81, 513–37.

K. J. McNamara & R. Feist 2006. New styginids from the Late Devonian of Western Australia – the last corynexochid trilobites. Journal of Paleontology 80, 981–92.

P. A. Parsons 1989. Environmental stresses and conservation of natural populations. Annual Review of Ecology and Systematics 20, 2949.

P. A. Parsons 1992. Fluctuating asymmetry: a biological monitor of environmental and genomic stress. Heredity 68, 361–4.

P. A. Parsons 1993 a. Stress, extinctions and evolutionary change: from living organisms to fossils. Biological Reviews 68, 313–33.

P. A. Parsons 1993 b. Developmental stability and the limits of adaptation: interactions with stress. Genetica 89, 245–53.

R. Wood 2004. Palaeoecology of a post-extinction reef: Famennian (Late Devonian) of the Canning Basin, north-western Australia. Palaeontology 47, 415–45.

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Geological Magazine
  • ISSN: 0016-7568
  • EISSN: 1469-5081
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