Is the fossil record of complex animal behaviour a stratigraphical analogue for the Anthropocene?

Abstract

Abstract:The base of the Cambrian System is recognised by a characteristic (marine) trace fossil suite assigned to the Treptichnus pedum Biozone that signals increasing complexity of animal behaviour, and demarcates the Cambrian from the (older) Ediacaran System (Proterozoic Eonathem). Ichnotaxa of the T. pedum Biozone are not the earliest trace fossils, and are preceded in the latest Proterozoic by a progressive increase in the diversity of trace-producing organisms and the communities they comprised, the structural and behavioural complexity of the trace fossils, and even the depth of burrowing in sediments. Parallels can be drawn with the increasing complexity of subsurface structures associated with human cities, which also reflect evolution of an increasingly complex community. Prior to the 19 th century these structures were limited and simple, but beginning with the development of London in the mid-19 th century as the world's first megacity, subsurface structures have become increasingly complex, reflecting the technologydriven behaviour of 20 th and 21 st century humans.

Human bioturbation, and the subterranean landscape of the Anthropocene

“…Williams et al, 2014;Zalasiewicz et al, 2014). M a n u s c r i p t Subterranean Anthropocene -highlights…”

“…Williams et al, 2014). It has no analogue in the Earth's 4.6 billion year history, and possesses some sharply distinctive features: for instance, the structures produced reflect a wide variety of human behaviour effected through Page 7 of 23 A c c e p t e d M a n u s c r i p t 7 tools or more typically mechanized excavation, rather than through bodily activity.…”

“…Shallow anthroturbation extends from metres to tens of metres below the surface, and includes all the complex subsurface machinery (sewerage, electricity and gas systems, underground metro systems, subways and tunnels) candidate, by Williams et al (2014). These buried systems, being beyond the immediate reach of erosion, have a much better chance of short-to mediumterm preservation than do surface structures made by humans.…”

A stratigraphical basis for the Anthropocene?

“…Human artefacts, routinely used as an indicator of age in archaeological investigations, could be used as an equivalent of the geological 'typefossils', with potentially greater resolution than biostratigraphical fossils (Barnosky 2013;Edgeworth 2013;Ford et al 2014). The evolution of these artefacts, which may be considered humanproduced trace fossils (Barnosky 2013;Williams et al 2013) or technofossils (Zalasiewicz et al 2014b), is a function of cultural dynamics rather than natural selection (Edgeworth 2013). These artefacts are prone in recent decades, certainly since the 1950s, to evolve from invention (equivalent to the biostratigraphical First Appearance Datum or FAD) to global distribution (equivalent to biostratigraphical acme) and then to obsolescence (equivalent to biostratigraphical rarity) within comparatively few years, as a function of the globalization of trade.…”

“…3) and, consequently, Gibbard & Walker (2013) argue it should not be used as a criterion for defining the Anthropocene. http://sp.lyellcollection.org/ Williams et al (2013) propose that the base of the Anthropocene should coincide not with the start of the Industrial Revolution, but with the radical evolution of the urban environment in the mid-eighteenth century. The increased size of conurbations resulted in the need to evolve subsurface transport and sewerage systems in order to keep them functioning.…”