A proposed framework for establishing and evaluating hypotheses about the behaviour of extinct organisms

Abstract

Reconstructing the possible behaviours of long extinct species, and especially those with no close living relatives, are naturally fraught with difficulty: data are often limited and hard to interpret. However, the field of palaeoethology has not been helped by a poor understanding of the range and plasticity of the behaviour of extant organisms, coupled with a tendency to generalize and over-interpret the limited information available. Here we attempt to construct a framework for the establishment of viable hypotheses about the behaviour of extinct organisms and the generation of support for, or testing of, these hypotheses. We advocate that it is preferable to under-interpret available data, than to suggest problematic hypotheses that may become accepted as correct.

A new horned and long-necked herbivorous stem-archosaur from the Middle Triassic of India

“…The above mentioned traits (i.e. costliness, positive allometry) characterize sexually selected –a subset of natural selection in which the resource at stake is mates 8 – features and, as a result, have been considered as key criteria to recognize secondary sexual characters in the fossil record 6, 7, 32–36 . Besides, the presence of substantial variation in the morphology of the horns of Shringasaurus indicus (size and shape) and their potential costliness weakens a species recognition hypothesis as a possible explanation.…”

Deep nesting in a lizard,déjà vudevil's corkscrews: first helical reptile burrow and deepest vertebrate nest

“…Diictodon) and how would this influence the 'environmental conditions' hypothesis for the evolution and maintenance of helical burrows? We propose a cautious approach when interpreting deep helical burrows and their tracemakers (Hone & Faulkes, 2014), partly because we know so little about burrowing in secretive, extant groups such as reptiles. For example, the nesting habits are unknown for most reptiles (Doody, Freedberg & Keogh, 2009), including 39 of the world's 53 species of monitor lizards known at that time (Doody et al, 2014).…”

“…In the meantime, the reconstruction of behaviours of long-extinct species remains fraught with difficulties (Benton, 2010). A major issue is the poor understanding of the range and plasticity of the behaviour of extant organisms, coupled with a tendency to generalize and over-interpret the limited fossil information available (Hone & Faulkes, 2014). On the other hand, ecologists, palaeoecologists and palaeoethologists share a common goal (Jackson, 2007;Rull, 2010) and cross-disciplinary research and interactions between the disciplines has increased (Flessa & Jackson, 2005;Willis et al, 2007).…”

Positive allometry for exaggerated structures in the ceratopsian dinosaur Protoceratops andrewsi supports socio-sexual signaling

“…The fundamental problem with trying to understand the biology of extinct organisms is that we cannot observe their behaviour directly and thus it is difficult to assess (Hone and Faulkes, 2014). As a consequence we have to fall back on more indirect assessments of whether a trait evolved through sexual selection, one of which is the rate of change of the traits in question during ontogeny (e.g., Tomkins et al, 2010;Knell et al, 2013a).…”