The origin of snake feeding

Abstract

whereas there is clearly not enough time for a 40-kyr obliquity control, thus excluding glacio-eustasy. Evaporite deposition occurred during precession maxima (insolation minima), during relatively dry periods when evaporation exceeded precipitation. This allowed the Mediterranean to form a giant brine, when out¯ow of dense Mediterranean waters into the Atlantic was restricted or obstructed by shallow sills in the western Mediterranean gateways. During precession minima (insolation maxima) and relatively wet periods, high freshwater runoff resulted in deposition of sapropellike sediments. As the average periodicity for precession in Neogene times is 21.7 kyr, the Lower Evaporite and the Upper Evaporite units have a duration of approximately 370 kyr and 175 kyr, respectively. Tentatively calibrating the evaporite and post-evaporite cycles to the insolation curve leaves only a small`Messinian gap' (between 5.59 and 5.50 Myr ago), during which the desiccation of the Mediterranean and the accompanying isostatic rebound processes 31 (tectonic tilting and erosion) must have occurred. M

At the feet of the dinosaurs: the early history and radiation of lizards

“…Similarly, a majority of recent analyses have placed snakes within Anguimorpha, although their precise relationships continue to be fiercely debated (e.g. Rieppel, 1988a,b;Caldwell & Lee 1997;Lee, 1997Lee, , 1998Lee & Caldwell, 1998Caldwell, 1999;Lee, Bell & Caldwell, 1999;Zaher & Rieppel, 1999;Cundall & Greene, 2000;Rage & Escuillié, 2000;Rieppel & Zaher, 2000 a, b;Tchernov et al, 2000;Rieppel & Kearney, 2001; see Coates & Ruta, 2000 for a comprehensive and impartial review).…”

First record of the mosasaur Platecarpus Cope, 1869 from South America and its systematic implications

“…mosasaurs, Tethysaurus Bardet et al, 2003 and aigialosaurs) and other reptiles remain controversial. Many workers (e.g., deBraga & Carroll, 1993) favour the idea that the mosasauroids are derived varanoid lizards (i.e., within the order Sauria), although recent studies (e.g., Lee et al, 1999) have revived an old theory (e.g., Cope, 1869) that the mosasauroids form a sister group to modern snakes (order Ophidia). Russell (1967) suggested that two ancestral lineages of the Mosasauridae; one Clidastes-like and one Platecarpus-like, gave rise to all subsequent mosasaur taxa.…”

‘Total evidence’ in phylogenetic systematics

“…The 'smoking gun' that clinched this explanation (Cleland 2002) was the discovery of corresponding home site marks on the inside of the body chamber of a Cretaceous ammonite, associated with radula scrape marks and with a limpet shell (Seilacher 1998). Under pressure from the theoretical preconception that snakes are descended from mosasauroids, however, Lee et al (1999) used the putative mosasaur bite marks on the ammonite first described by Kauffman and Kesling (1960) to reconstruct jaw movements in mosasaurs. Their conclusion was that the jaw movements of mosasaurs corresponded to a pattern that is intermediate between that of terrestrial lizards and snakes such as pythons.…”