Ordovician–Silurian Lilliput crinoids during the end-Ordovician biotic crisis

Abstract

Coincident with the end-Ordovician (end-Katian for crinoids) biodiversity crash, crinoids from Anticosti Island, Quebec, experienced a statistically significant reduction in body size, an evolutionary trend termed the ''Lilliput Effect''. This decrease in body size occurred for the fauna as a whole, and data indicate that neither dominant Ordovician nor dominant Silurian clades experienced preferential size decrease. Because the post-extinction fauna with a diminished size is composed of largely new taxa, this example of the Lilliput Effect is regarded as the miniaturization mode. The miniaturization occurred very rapidly; however, the recovery on Anticosti Island did not occur for as many as 7 Ma. This macroevolutionary asymmetry, as demonstrated in many other studies, highlights the need to preserve the biodiversity present on Earth today.

Body size changes in bivalves of the family Limidae in the aftermath of the end‐Triassic mass extinction: the Brobdingnag effect

“…) or the taxonomic rank is often generic or higher (e.g. Borths & Ausich ; Chen et al . ; Chu et al .…”

Rostrum size differences between Toarcian belemnite battlefields

“…This socalled Lilliput effect (Harries and Knorr, 2009) has not only been reported for the Toarcian Oceanic Anoxic Event but also for other extinction events (e.g. Twitchett, 2007;Harries and Knorr, 2009;Borths and Ausich, 2010;Rego et al, 2012;Sogot et al, 2014). However, the evolutionary and ecological importance of the Lilliput effect remains poorly understood.…”

“…Furthermore, because of physiological differences, not all organisms necessarily exhibit a body size reduction in the face of warming or other environmental stresses (Gardner et al, 2011;Ohlberger, 2013). Some authors even consider that, in some cases, the body size reduction might reflect a preservation or collection artefact (McGowan et al, 2009;Brayard et al, 2010).…”

U-Pb (zircon) age constraints on the timing and duration of Wenlock (Silurian) paleocommunity collapse and recovery during the "Big Crisis"

“…Datum 1 marks the onset of the biotic crisis among conodonts and is identifi ed by the last appearance datum (LAD) of Kockelella ortus ortus and Ozarkodina sagitta sagitta (indicating the top of the O. sagitta sagitta zone and the base of the overlying O. bohemica longa zone) and appears to have been the most severe conodont extinction level . Datum 1.5 marks the disappearance of most of the Walliserodus lineage as well as Pseudooneotodus linguicornis, whereas datum 2 had less profound effects on the conodont fauna (in terms of extinction) and is most noted for its changing population dynamics and other "event effects" (Jeppsson et al, 1995;Männik et al, 2002;Jeppsson and Calner, 2003;Calner and Jeppsson, 2003;"event effects"-Jeppsson , 1998;Calner, 2005;Sticanne et al, 2006;Borths and Ausich, 2011). The generally impoverished low-diversity "survivor" fauna continues through the Oz.…”