An Early Devonian arthropod fauna from the Windyfield cherts, Aberdeenshire, Scotland

Abstract

ABSTRACT. New terrestrial and freshwater arthropods are described from the Windy®eld cherts, a suite of silici®ed sinters deposited 700 m north-east of the Rhynie cherts and part of the same Early Devonian hot-spring complex. The diverse assemblage consists of Heterocrania rhyniensis (Hirst and Maulik, 1926a), here recognized as a euthycarcinoid; scutigeromorph centipede material assigned to Crussolum sp.; the crustacean Lepidocaris; trigonotarbid arachnids; a new arthropod of myriapod af®nities named Leverhulmia mariae gen. et sp. nov.; and the distinctively ornamented arthropod cuticle of Rhynimonstrum dunlopi gen. et sp. nov. The Leverhulmia animal preserves gut content identifying it as an early terrestrial detritivore. Abundant coprolites of similar composition and morphology to the gut contents of the euthycarcinoid crowd the matrix. Chert texture, faunal associations, and study of modern analogues strongly suggest that the terrestrial arthropods were ubiquitous Early Devonian forms with no particular special adaptation to localized conditions around the terrestrial hot-spring vents. The aquatic arthropods represent biota from ephemeral cool-water pools in the vicinity of the hot-spring vents.KEY WORDS: Rhynie, arthropod, hot-springs, chert, Devonian, euthycarcinoid.T H E Early Devonian Rhynie chert Konservat-Lagersta Ètte continues to yield important information on an early terrestrial ecosystem preserved almost in its entirety. Intensive drilling, core recovery and trenching carried out in the Rhynie SSSI (Site of Special Scienti®c Interest) has established that the cherts originated through the deposition of siliceous sinter in the subaerial zone of a hydrothermal hot-spring complex (Rice et al. 2002). During the same phase of exploration, new chert was collected from the nearby Windy®eld hot-spring complex ®rst noted by Trewin and Rice (1992) . Prospecting the Windy®eld cherts for arthropods has led to the discovery of a varied fauna of both terrestrial and aquatic arthropods. We report the initial ®nds and compare them with those of the Rhynie cherts.The Windy®eld cherts exhibit the same general ®eld relations and sedimentological setting as the Rhynie cherts: impersistent pods of chert, bounded by ®ne-grained carbonaceous sandstones and variable thicknesses of hydrothermally altered sticky blue clays (Text-®g. 2). However, the Windy®eld¯oat blocks differ markedly in texture, colour, and biotic content from those previously recorded from the Rhynie chert site (Powell et al. 2000a). To date, trigonotarbid arachnids, crustaceans, mites, and a collembolan have been described from the Rhynie cherts (Kevan et al. 1975). Trewin (1994) provided a review of the arthropod fauna, but omitted two problematical forms, Heterocrania Hirst and Maulik, 1926b and Rhyniognatha Tillyard, 1926. We now assign Heterocrania to the euthycarcinoids, but can shed no further light on Rhyniognatha. Documentation of the new arthropods in the Windy®eld cherts substantially increases our knowledge of the biota, and of the plant-a...

A timeline for terrestrialization: consequences for the carbon cycle in the Palaeozoic

“…This material samples the genus Crusslolum, also known from the Rhynie and Windyfield cherts of Scotland [64] and the Middle Devonian (Givetian) of Gilboa, New York [65], and identified as a stem-group scutigeromorph [62]. The forcipules by which all centipedes inject venom are developed in Crussolum as in extant scutigeromorphs [64], and membership of this geologically ancient material in the crown group of Chilopoda, a wholly predatory clade, indicates a long history of predation in centipedes.…”

Early Terrestrial Animals, Evolution, and Uncertainty

“…The oldest of these, from the Late Silurian of the Welsh Borderlands in England, belong to a genus, Crussolum, that is better known from various body parts in the Early and Middle Devonian (as for many examples in this article, the Devonian fossils come from the Rhynie cherts in Scotland and Gilboa in New York State- Fig. 4b has an example; Anderson and Trewin 2003;Shear and Bonamo 1988). Crussolum is unambiguously a member of Scutigeromorpha, a group that includes 100 living species that mostly live in the tropics and subtropics, but best known from the "house centipede," Scutigera coleoptrata, an introduced species in many temperate parts of the world (Fig.…”

A unique winged euthycarcinoid from the Permian of Antarctica

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