Tawa

Life restoration of Tawa hallae created by Jeffrey Martz (Petrified Forest National Park, AZ)

Life restoration of Tawa hallae created by Jeffrey Martz (Petrified Forest National Park, AZ)

Tawa is an early theropod from the Late Triassic. The genus is named after the Hopi word for the Puebloan sun god. It was a bipedal carnivore, estimated around 2.5 m in length, and weighing about 15 kg. A basal theropod, Tawa shares physical characteristics with coelophysoids and herrerasaurids, and its discovery supports the theory that dinosaurs originated in the southern supercontinent of Gondwanna, before diversifying as Pangea split apart.

Silhouette of Tawa hallae.

Life reconstruction of Tawa hallae

Tawa

A traditional dish from Shkoder, consisting of carp fish from Shkodra lake. It is commonly sliced and baked with tomato sauce in a tava dish.

This diagram illustrates how scientists believe the dinosaur group theropoda shall be classed in a phylogenetic tree, besides Sauropoda and Pterosauria. The main reason of this diagram is to show groups or families which had respiratory system like birds. AS in the diagram is abbreviations for "Airsacs", and ASW means "AirSacs supported by immobile femur and a knee-driven Walk". BL means "Bellow lungs". Airsacs are known in many different theropods, as well as in birds, which most scientists believe are descendants of dinosaurus. Air sacs are found in the primitive Tawa hallae,[1] the abelisaurid Majungasaurus,[2] as well as Allosauroids like Aerosteon.[3] There is also evidence for respiratory systems like penguinss in Deinonychosaurians.[4] The primitive bird Archaeopteryx also had airsacs (Bonde and Christiansen, 2000). It is very likely that Deinonychosaurians had airsacs. We don't know whether Deinonychosauria had a walking/breathing system with immobile thighbones, ASW (like birds) or movable thighbones. However, some people suggsest coeluosaurs had the same type of leg movement as birds ("kneedriven walking").[5] Bellow lungs are lungs like our own, which alternately is filled with air, and thereafter emptied, after which you take a new breath. This type of lungs exist in mammals, most reptiles, and most amphibians (although some frogs get their oxygen through the skin). There is no evidence for airsacs in Ornithischia, so the likely had bellow lungs. References.= ↑ (see the video at http://www.nsf.gov/news/special_reports/tawa/) ↑ (Claessens & O'connor, 2006). ↑ Alcober O.A, Sereno P.C, Larsson H.C.E et.al (2008), "Evidence for Avian Intrathoracic Air Sacs in a New Predatory Dinosaur from Argentina", Public Library of Science Journals. ↑ http://www.stumbleupon.com/su/20q5Z4/news.bbc.co.uk/2/hi/science/nature/7081166.stm ↑ http://www.geol.umd.edu/~tholtz/G104/lectures/104coelur.html.

Digital drawing of the known skeletal remains of Chindesaurus byansmalli. Known elements represented in white and unknown in gray. Reconstructed elements are based on Tawa hallae

Digital drawing of the known skeletal remains of Caseosaurus crosbyensis. Known elements represented in white and unknown in gray. Reconstructed elements are based on Tawa hallae

Life restoration of Tawa hallae created by Jeffrey Martz (Petrified Forest National Park, AZ)

Digital drawing of the known skeletal remains of Chindesaurus byansmalli. Known elements represented in white and unknown in gray. Reconstructed elements are based on Tawa hallae