This is the "Fossil Friday" post #207. Expect this to be a somewhat regular feature of the website. We will post any fossil pictures you send in to [email protected]. Please include a short description or story. Check the #FossilFriday Twitter hash tag for contributions from around the world!
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On a recent field trip to a couple Mazon Creek localities, we met Patrick Blomenkemper of the Field Museum, who has been researching the fossil flora from the Dead Sea region of Jordan. The locality dates to the late Permian and has been called "A Late Permian Garden of Delights".
Patrick co-authored the paper "The fossil flora of the Dead Sea region, Jordan - A late Permian Garden of Delights", which was published in the Journal of Palaeosciences. These rarely seen and exquisitely preserved fossils provide essential insights into plant evolution.
Abstract
The Umm Irna Formation, Jordan, holds one of the most peculiar late Permian plant–fossil assemblages worldwide. Over the last decades of field work, several localities close to the eastern shore of the Dead Sea have yielded a highly diverse ‘mixed flora’ of mesic to xeric environments encompassing elements that are typical either for different floral realms or for different time periods of Earth History. Taxa typical for particular floral realms include, e.g. Cathaysian gigantopterids and Lobatannularia, Euramerican conifers such as Otovicia hypnoides, or the characteristic Gondwanan seed ferns Glossopteris and Dicroidium. Moreover, most taxa are typical for the Permian, some assemblages have also yielded precocious occurrences of taxa that have so far been considered typical for the Mesozoic, such as Umkomasiaceae, Bennettitales, and podocarp conifers. In most cases, fossils from the Umm Irna Formation show well–preserved cuticles that allow sound systematic placement and contribute to the reconstruction of dispersed plant parts into whole–plant–taxa. Altogether, the Umm Irna Formation provides an exceptional window into depositional environments and vegetation types that are rarely preserved in the fossil record but that are crucial for our understanding of plant evolution.
From the paper "A treasure trove of peculiar Permian plant fossils" of which Patrick was the lead author.
Among these, especially the characteristic bifurcate fronds of Dicroidium—an otherwise typical index taxon of the Gondwanan Triassic (e.g., Anderson and Anderson 1983, 2003) constitute some of the most spectacular fossil highlights (Kerp et al. 2006; Abu Hamad et al. 2008, 2017; Blomenkemper et al. 2018). In many cases, the plant material is essentially mummifed, and cuticles simply peel of the rock (Fig. 1). Microscopic analysis of the epidermal anatomy documented in the overlying cuticle (Fig. 2) permits a precise systematic placement and a reassembly of dispersed plant parts into whole-plant taxa (Kerp 1990). The occurrence of this diverse Dicroidium fora in the Permian tropics has major implications for biostratigraphy and biogeography, since it represents the oldest and northernmost record for these plants (Kerp et al. 2006; Abu Hamad et al. 2008).
These fossils are beautifully preserved. It's interesting to see how similar some are to what we see in Mazon Creek, even though they are about 50 million years younger. Thanks for sharing these amazing images and interesting papers, Patrick!
Dicroidium irnense, almost complete frond with dichotomy of the frond axis.
Large frond of Dicroidium irnense from the late Permian Umm Irna Formation, Jordan.
Upper surface of a complete pinnule of Dicroidium irnense
Lower surface of a complete pinnule of Dicroidium irnense
Otovicia hypnoides
Cuticles of Dicroidium jordanense
The deposit preserves more than plants... here's a coprolite fossil from the deposit.
