Tag Archives: Triassic

A Middle Triassic stem-turtle and the evolution of the turtle body plan

A new stem-turtle, Pappochelys rosinae, is structurally and chronologically intermediate between the stem-turtles Eunotosaurus and Odontochelys and is from the late Middle Triassic of Germany (Ladinian; ∼240 million years ago). The three taxa share anteroposteriorly broad trunk ribs that are T-shaped in cross-section and bear sculpturing, elongate dorsal vertebrae, and modified limb girdles. Pappochelys closely resembles Odontochelys in various features of the limb girdles. Unlike Odontochelys, it has a cuirass of robust paired gastralia in place of a plastron. Pappochelys provides new evidence that the plastron partly formed through serial fusion of gastralia. The skull of Pappochelys has small upper and ventrally open lower temporal fenestrae, supporting the hypothesis of diapsid affinities of turtles.

http://www.nature.com/nature/journal/vaop/ncurrent/full/nature14472.html

Life reconstruction:

http://www.npr.org/sections/thetwo-way/2015/06/24/416657576/how-the-turtle-got-its-shell

Damn, this is HOT!! – Lethally Hot [Sea] Temperatures During the Early Triassic Greenhouse

Review:

http://www.sciencemag.org/content/338/6105/336.full

Bottjer, D. J., 2012: Life in the Early Triassic Ocean.
–Science: Vol. 338, #6105, pp. 336-337 [doi: 10.1126/science.1228998]

Abstract:

“In the next 100 years, it is projected that Earth will move to a greenhouse climate state. The future ocean will not only be hotter but also more acidic and will contain extended zones with reduced oxygen. Study of past periods of global warming helps to project what Earth and its biota will be like in this new state and what the journey to that state will entail. On page 366 in this issue, Sun et al. show that beginning with the end-Permian mass extinction (∼252.6 million years ago) and continuing for the next 5 million years, Earth’s oceans were extremely hot, with stressful and commonly lethal effects on ocean life.”

Article.

Sun, Y., Joachimski, M. M., Wignall, P. B., Yan, C., Chen, Y., Jiang, H., Wang, L. & Lai, X., 2012: Lethally Hot Temperatures During the Early Triassic Greenhouse.
–Science: Vol. 338, #6105, pp. 366-370 [doi: 10.1126/science.1224126]

Abstract:

“Global warming is widely regarded to have played a contributing role in numerous past biotic crises. Here, we show that the end-Permian mass extinction coincided with a rapid temperature rise to exceptionally high values in the Early Triassic that were inimical to life in equatorial latitudes and suppressed ecosystem recovery. This was manifested in the loss of calcareous algae, the near-absence of fish in equatorial Tethys, and the dominance of small taxa of invertebrates during the thermal maxima. High temperatures drove most Early Triassic plants and animals out of equatorial terrestrial ecosystems and probably were a major cause of the end-Smithian crisis.”

–Mikko