Sprecher
Beschreibung
The Early Devonian Rhynie chert is one of the most exceptional fossil archives known for exquisitely preserved plants, microbes and animals. These fossils with cellular-scale structures have provided unique insights into early terrestrial life. The Rhynie animal assemblage is composed of various arthropods, including hexapods, myriapods and arachnids, implying a complex faunal structure and ecosystem. Although many of the arthropods are well described through the investigation of classical thin sections, we possess less information about their 3D morphology, especially of larger individuals, as fossils remain hidden within the solid chert matrix and are often destroyed when making thin sections. This is a critical limitation for understanding their 3D form and ecology. Here we present the entire 3D reconstructions and high-density community of Palaeocharinus, millimetre-sized principal predators in the Rhynie ecosystem, via the Digital Fossil Mining system. Their large lateral eyes, with anterior elevation, suggest wide frontal fields of view, and their raptorial chelicerae, movable from downwards to forwards, were likely useful for capturing and holding prey during pre-oral digestion. The sedimentary facies and mode of occurrence indicate that the featured chert block preserves Palaeocharinus and plenty of surrounding plants in situ, and that their annual population was high. These findings show that the Rhynie environment, one of the earliest land ecosystems, was covered by a 'tiny forest' of centimetre-sized plants capable of sustaining abundant adaptive predators.