Document Type


Publication Date



A new species of a dielasmid brachiopod from the Triassic Saharonim Formation of Makhtesh Ramon, southern Israel, was discovered in Anisian-Ladinian limestones that alternate with calcareous shales. The environment of deposition was an open shelf with normal salinity. The new species is homeomorphic with Paleozoic forms, but may not belong to the genus Dielasma; however, it may be a species of Tunethyris, a Triassic genus from Tunisia. If the Triassic specimens belong to the Paleozoic genus Dielasma, an important new Lazarus genus is added to the systematic literature. However, if the specimens belong to the Triassic Tunethyris, there are important paleobiogeographic considerations to be noted, such as the significance of the enigmatic Ladinian crisis and the influence of the Hispanic Corridor, an immature seaway connecting the western Tethys with eastern Panthalassa that may have been open sporadically during the Late Triassic and affected brachiopod distribution. Points favoring the selection of Tunethyris are: 1. The orientation of the crura in the new species is slightly different from Paleozoic dielasmids, especially D. elongatum from the Permian of Germany; 2. the anatomy of Tunethyris punica from the Norian of Tunisia is very similar to the new species and the anterior commissure of both is sulicplicate, a feature not found in Paleozoic forms; 3. The loop of the Israeli brachiopods is acuminate. In addition to other anatomical characters that support the erection of a new species, Tunethyris calzada has a septalium supported by a median septum whereas the septalium in the brachiopods from Makhtesh Ramon rests on the valve floor.

Feldman_Howard_Or.pdf (117 kB)

Publisher's Statement

Abstract © 2017 The Geological Society of America. Abstract reprinted with the permission of the publisher for noncommercial use - please see the abstract itself for additional information. The original abstract can be found here. Poster © 2017 Authors.

Included in

Paleontology Commons



To view the content in your browser, please download Adobe Reader or, alternately,
you may Download the file to your hard drive.

NOTE: The latest versions of Adobe Reader do not support viewing PDF files within Firefox on Mac OS and if you are using a modern (Intel) Mac, there is no official plugin for viewing PDF files within the browser window.