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Amblypygi Look for this name in NCBI Wikipedia Animal Diversity Web
Wolfe et al. 2016
node minimum age |
The genus Graeophonus was originally described from the Sydney Basin, Cape Breton Carboniferous Coal Measures, Nova Scotia, Canada,which corresponds to Westphalian in age (Dunlop et al., 2007; Gileset al., 2002; Scudder, 1890a). Further studies are needed on the Canadian material, so the minimum age was taken from the oldest European specimen (which is roughly the same age as the Cape Breton specimen)from the British Middle Coal Measures (Coseley, Stafffordshire), which is Westphalian B (or Duckmantian) at the youngest (Waters et al.,1994; Waters and Davies, 2006). U-Pb dating of zircons constrains the upper boundary of the Duckmantian to 313.78 Ma ± 0.08 Myr (Pointon et al., 2012), so a minimum age for G. anglicus is 313.70 Ma.
node maximum age |
A soft maximum constraint comes from the oldest chelicerate W. barbarahardyae from the Emu Bay Shale on Kangaroo Island, SouthAustralia, which has been correlated based on trilobite biostratigraphy to the upper part of the P. janeae Zone in mainland South Australia (Jell in Bengtson et al., 1990; Fig. 2 in Jago et al., 2012). As this is equivalent to the Canglangpuan Stage in South China and the late Botoman inSiberia (Gehling et al., 2011, Fig. 9), the Emu Bay Shale can be dated to Cambrian Series 2, Stage 4, providing a maximum age of ~514 Ma.
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NHMUK In. 31233
G. anglicus was redescribed by Dunlop et al. (2007) as a member of the Amblypygi crown group. This was based on several morphological character comparisons to living members, such as the pedipalp femur with dorsal spination similar to Paracharon (the monotypic extant species of the family Paracharontidae). G. anglicus, unlike Paracharon, has a pear-shaped ocular tubercle, suggesting it was not blind. G. anglicus is inferred to be on the stem lineage of Paracharontidae, and thus, crown group Amblypygi (Dunlop et al., 2007).
Dunlop, J.A., Zhou, G.R.S., Braddy, S.J., 2007. The affinities of the Carboniferous whip spider Graeophonus anglicus Pocock, 1911 (Arachnida: Amblypygi). Earth Environ. Sci. Trans. R. Soc. Edinb. 98, 165–178.
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