Now, that's a bug!
The largest arthropod in Earth history: insights from newly discovered
Arthropleura remains (Serpukhovian Stainmore Formation,
Northumberland, England)
Abstract
Arthropleura is a genus of giant myriapods that ranged from the early
Carboniferous to Early Permian, with some individuals attaining
lengths >2 m. Although most of the known fossils of the genus are
disarticulated and occur primarily in late Carboniferous
(Pennsylvanian) strata, we report here partially articulated
Arthropleura remains from the early Carboniferous Stainmore Formation
(Serpukhovian; Pendleian) in the Northumberland Basin of northern
England. This 76 × 36 cm specimen represents part of an exuvium and is
notable because only two comparably articulated giant Arthropleura
fossils are previously known. It represents one of the largest known
arthropod fossils and the largest arthropleurid recovered to date, the
earliest (Mississippian) body fossil evidence for gigantism in
Arthropleura, and the first instance of a giant arthropleurid body
fossil within the same regional sedimentary succession as the large
arthropod trackway Diplichnites cuithensis. The remains represent
12–14 anterior Arthropleura tergites in the form of a partially
sand-filled dorsal exoskeleton. The original organism is estimated to
have been 55 cm in width and up to 2.63 m in length, weighing c. 50
kg. The specimen is preserved partially in three dimensions within
fine sandstone and has been moderately deformed by synsedimentary
tectonics. Despite imperfect preservation, the specimen corroborates
the hypothesis that Arthropleura had a tough, sclerotized exoskeleton.
Sedimentological evidence for a lower delta plain depositional
environment supports the contention that Arthropleura preferentially
occupied open woody habitats, rather than swampy environments, and
that it shared such habitats with tetrapods. When viewed in the
context of all the other global evidence for Arthropleura, the
specimen contributes to a dataset that shows the genus had an
equatorially restricted palaeogeographical range, achieved gigantism
prior to late Paleozoic peaks in atmospheric oxygen, and was
relatively unaffected by climatic events in the late Carboniferous,
prior to its extinction in the early Permian.
Open access:
https://jgs.lyellcollection.org/content/early/2021/11/19/jgs2021-115