“…Alternatively, changes in speciation rates from the Neogene to the Pleistocene may not be related to carrying capacities if: 1) rates of speciation were directly associated with environmental instability and habitats changed more rapidly in the Neogene than the Pleistocene, 2) rates were time dependent and reduced as groups fail to diversify with changing environments, or 3) where extinction rates were suitably high (Vrba 1985;Rosenzweig 1995;Pigot et al 2010;Pyron and Burbrink 2012a;Quental and Marshall 2013;Moen and Morlon 2014). This paradox, where standing diversity was most likely generated in the Pleistocene yet may also have been a period of declining diversification rates, has been addressed in other arboreal prey, such as lizards or frogs, may be required for successful capture, but we note that some aglyphous taxa have enlarged rear teeth, yet with no groove, but may still envenomate prey (Razafimahatratra et al 2015). Further work on mandibular and tooth morphology here, which includes hinged teeth, gaps in tooth rows, enlarged anterior teeth, and edentulous jaws (Savitzky 1983;Cadle 1996Cadle , 1999Cadle , 2003Cadle , 2014, integrated with prey capture, envenomation, and production or constitution of venom should be examined for a more nuanced view of gemsnake trait evolution.…”