Arrow Poison and Arrow without Poison

Central and South America are home to a remarkable diversity of frogs, coming in nearly all the shapes and sizes a frog can possibly come in. Among this diversity, probably the most famous representatives are the arrow-poison frogs of the Dendrobatidae. Two dendrobatid frogs of two different subfamilies: dyeing dart frog Dendrobates tinctorius (Dendrobatinae, left)… Continue reading Arrow Poison and Arrow without Poison


Pair of mounted skeletons of Dimetrodon, copyright D’Arcy Norman. Belongs within: Synapsida. Contains: Therapsida. The Sphenacodontidae are a group of carnivorous ‘pelycosaurs’ known from the later Carboniferous to the Middle Permian, suggested by Kemp (1988) to be paraphyletic to the therapsids. <==Sphenacodontidae K88 |  i. s.: Secodontosaurus BH04 |         Sphenacodon Marsh 1878 D07 |           |–S. ferocior… Continue reading Sphenacodontidae


Reconstruction of Cymbospondylus natans, copyright Teratophoneus. Belongs within: Ichthyosauria. Contains: Thunnosauria. The Hueneosauria are a clade of ichthyosaurs defined by Maisch & Matzke (2000) as the most exclusive clade including Mixosaurus cornalianus and Ophthalmosaurus icenicus. Synapomorphies (from Maisch & Matzke 2000): External naris placed largely laterally; anterior margin of orbit regularly rounded; ramus occipitalis of… Continue reading Hueneosauria


Reconstruction of Grippia longirostris, copyright Dmitry Bogdanov. Belongs within: Reptilia. Contains: Hueneosauria. The Ichthyosauria are a major clade of marine reptiles known from the Lower Triassic to the lower Upper Cretaceous, members of which evolved a remarkably fish-like body form (Maisch & Matzke 2000). Characters (from Maisch & Matzke 2000): Premaxillary rostrum elongate; naris displaced… Continue reading Ichthyosauria


Reconstruction of Pareiasaurus serridens, copyright Nobu Tamura. Belongs within: Parareptilia. The Procolophonia are a clade of reptiles known from the mid-Permian to the late Triassic, including the large armoured Pareiasauria and the lizard-like Procolophonoidea. Some authors have also included the modern turtles in this clade. Synapomorphies (from Laurin & Reisz 1995): Pineal foramen close to… Continue reading Procolophonia


Reconstruction of Metoposaurus krasiejowensis, copyright Dmitry Bogdanov. Belongs within: Stereospondylomorpha. The Trematosauria are a clade of temnospondyls defined by Yates & Warren (2000) as including all species closer to Trematosaurus than Parotosuchus. Synapomorphies (from Yates & Warren 2000): Interorbital space greater than 50% of skull width at mid orbital level; stapedial foramen absent; sharp rimmed… Continue reading Trematosauria


Reconstruction of Milleretta rubidgei, copyright Nobu Tamura. Belongs within: Reptilia. Contains: Procolophonia. The Parareptilia are a clade corresponding to the greater part of the previously recognised ‘Anapsida’ group of reptiles lacking a temporal fenestra in the skull. They are known from the Upper Permian and Triassic; their survival after this time depends on whether the… Continue reading Parareptilia