Australia/Canada Connection:

Discussion in 'Earth Science' started by paddoboy, Jun 16, 2020.

  1. paddoboy Valued Senior Member

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    https://phys.org/news/2020-06-fossil-discovery-million-year-old-canada-australia.html

    New fossil discovery shows 50 million-year-old Canada-Australia connection:

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    The new fossil lacewing species from British Columbia, Canada, with an almost complete wing. Credit: The Canadian Entomologist. Used by permission.

    The discovery of a tiny insect fossil is unearthing big questions about the global movement of animals and the connection to changes in climate and shifting continents across deep time. The fossil, estimated to be 50 million years old, was found in rocks near the city of Kamloops, British Columbia, but today its relatives live exclusively in Australia.

    The finding is the latest in a pattern of discoveries that are leading experts to contemplate a Canada-Australia connection not previously considered. Paleontologists Bruce Archibald of Simon Fraser University and the Royal British Columbia Museum and Vladimir Makarkin of the Russian Academy of Sciences in Vladivostok published their findings in The Canadian Entomologist.

    According to Makarkin, the fossil is part of the "split-footed lacewing" family. Little is known about this group over the 66-million-years following the extinction of the dinosaurs. "These fossils are rare," he says. "This is only the fourth one found from this time-span world-wide, and it's the most completely preserved. It adds important information to our knowledge of how they became modern."

    The paleontologists identified the fossil by the characteristic network of veins covering its wings. They emphasize that fossils like the new lacewing species help in understanding large-scale patterns of the modern distribution of life across the globe.

    Previous fossil insects of this age found in B.C. and neighboring Washington have shown connections with Pacific-coastal Russia to the west and with Europe to the east—patterns that are not surprising since the northern continents were connected then.

    more at link......
    extract:
    "The Australian connection is more puzzling though, as there is no such clear land connection. That continent was closer to Antarctica then and farther from Asia than today, leaving formidable ocean barriers for life to disperse between it and Canada's west coast".
    the paper:
    https://www.cambridge.org/core/jour...ic-nymphidae/35D0336C428FCDC02285C8B3E5FC947E

    A new genus and species of split-footed lacewings (Neuroptera) from the early Eocene of western Canada and revision of the subfamily affinities of Mesozoic Nymphidae

    Abstract

    A new genus and new species of Nymphidae (Neuroptera) is described from the Ypresian Okanagan Highlands locality of Falkland, British Columbia, Canada: Epinesydrion falklandensisnew genus, new species. This is only the fourth known Cenozoic adult specimen, and all others are less complete. It is the second specimen from the Okanagan Highlands. Currently Nymphidae has two recognised subfamilies. All Cenozoic fossils are confident members of the Nymphinae, but the subfamily assignments of almost all Mesozoic genera are problematic. The Late Cretaceous Dactylomyius is the only genus that might belong to Myiodactylinae. The rest may belong to the undefined stem groups of the family or to the Nymphinae, with varying levels of probability. Mesonymphes sibirica is transferred to Nymphites Haase: N. sibiricus (Ponomarenko), new combination; Sialium minor to Spilonymphes Shi, Winterton, and Ren: Spilonymphes minor (Shi, Winterton, and Ren), new combination; “Mesonymphes” apicalis does not belong to Mesonymphes Carpenter and may not even belong to the Nymphidae. The fossil record of the family occurs across much of the globe, but today they are restricted to Australia, New Guinea, and possibly the Philippines. Modern Nymphinae is only found in Australia. This may result from a requirement of frost-free climates, which were more widespread in the past.

     

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