Tag: fossils

Jurassic Park in Eastern Morocco: Paleontology of the Kem Kem Group

The Kem Kem beds in Morocco are famous for the spectacular fossils found there, including at least four large-bodied non-avian theropods, several large-bodied pterosaurs and crocodilians. In their study, published in the open-access journal Zookeys, an international group of scientists, led by Dr. Nizar Ibrahim and Prof. Paul Sereno, evaluate the geological and paleontological significance of the study area.

The Kem Kem beds in Morocco are famous for the spectacular fossils found there, including at least four large-bodied non-avian theropods, several large-bodied pterosaurs and crocodilians.

Now, in a new geology and paleontology monograph, that reveals much more about the famous Kem Kem beds in Morocco, Dr. Nizar Ibrahim from the University of Detroit Mercy, Prof. Paul Sereno from the University of Chicago, and a team of international scholars from the United States, Europe and Morocco, have put together a comprehensive story that is published in the open-access journal Zookeys.

The aim of the new research is to provide the international community with an in-depth review of the rocks and fossils of the region. It reviews the geology and paleontology of this famous but surprisingly understudied area, describing and formally naming the strata and summarizing all of the preserved life forms, from fragile plants and insects to massive dinosaurs. The monograph also paints a picture of life as it once was some 95 million years ago by describing the paleoenvironments of the region, and the unusual predator-dominated fauna.

In 1996 Prof. Sereno and colleagues introduced the informal term “Kem Kem beds” for this fossil-rich escarpment. In this monograph, the authors review the original tri-level proposal for the region by French geologist Choubert (his informal “trilogie mésocretacée”) and propose the Kem Kem Group for the entire package of rock with two new names for the dinosaur-bearing layers based on the richest fossil sites, the Gara Sbaa and Douira formations.

The region is famous for the prodigious fossils found in all of these units, many derived from commercial fossil collecting, which obscures the precise location and level of the specimens. The monograph is the first work to pinpoint where many of the most important finds were made. Over the last 25 years in particular, paleontologists have brought to light a diverse array of new vertebrate fossils including at least four large-bodied non-avian theropods, several large-bodied pterosaurs, crocodilians, turtles and an array of sharks and bony fish.

To put a comprehensive story together on the Kem Kem, the authors of the monograph visited collections of Kem Kem fossils around the world and led many expeditions to the region. Fossil and geological data reviewed in the monograph is derived from a number of different sources. A University of Chicago-led major expedition in 1995 generated a wealth of geological and paleontological data, as did later expeditions involving teams from the University College Dublin, the University of Portsmouth, the Faculté des Sciences Aïn Chock, the Muséum national d’Histoire naturelle, the University Cadi Ayyad, the Museo Civico di Storia Naturale (Milan), and the University of Detroit Mercy.

One of the key features of the Kem Kem assemblage is the presence of several large-bodied theropods, a group of dinosaurs that includes all of the meat-eaters. Most famous among these from the Kem Kem include the sail-backed Spinosaurus and the sabre-toothed Carcharodontosaurus.

Most fossils in the Kem Kem region are discovered as isolated fragmentary pieces weathered from sandstones. Only four partial dinosaur skeletons or skulls have been recovered, which include the long-necked sauropod Rebbachisaurus garasbae and the theropods Deltadromeus agilis, Carcharodontosaurus saharicus and Spinosaurus aegyptiacus. These Kem Kem theropods are among the largest known dinosaurian predators on record reaching adult body lengths in excess of 12 meters.

“Given the continued input of new specimens and the continuing expansion of paleontological research, we predict that diversity in the Kem Kem Group will increase substantially in the coming decades. Based on our review of existing collections, this increase will include scores of taxa from the pond locality Oum Tkout including nonvertebrates, such as plants, insects, and ostracods, as well as an array of actinopterygian fish. We also anticipate a continuing trickle of new terrestrial vertebrates that will be named on better preserved specimens that are diagnostic at present only at the familial level, including turtles and various kinds of archosaurs. As nearly half of the reptilian families listed are indeterminate, better preserved specimens will offer future opportunities to recognize new reptilian genera” ,
share the authors.

Predators abound on land, in the air and in water some 95 million years on the shores of northern Africa —as shown by the abundant fossils in the Kem Kem region.
Large herbivores, such as the long-necked sauropod *Rebbachisaurus*, could have been hunted or scavenged by several large predators.
Credit: Artwork by Davide Bonadonna
License: CC-BY 4.0

“In summary, the Kem Kem assemblage of non-vertebrates and vertebrates is likely to continue to show dramatic increase in diversity in the coming decades. Nonetheless, the array of taxa currently known, which extends from plants across a range of aquatic and terrestrial vertebrates, is sufficiently mature to allow a summary of the vertebrate assemblage and a discussion of its paleoecological contex”,
conclude the researchers.

In his earlier research, a famous paleontologist from the University of Chicago Prof. Paul Sereno has described many outstanding dinosaur discoveries, including new Cretaceous crocodilians from the Sahara and two new fanged vegetarian dinosaur dwarfs (called heterodontosaurids).

The most famous of Kem Kem dinosaurs, the semi-aquatic giant *Spinosaurus*, and the most common of Kem Kem fossils, the giant sawfish *Onchopristis*, tangle in the shallow coastal waters on a warm Late Cretaceous day.
Credit: Artwork by Davide Bonadonna
License: CC-BY 4.0

The wealth of aquatic life, including shrimp, bony fish, lungfish and giant lobe-finned coelacanths, supported a remarkable array of predators, including the fish-eating sail-backed *Spinosaurus* and toothless pterosaur *Alanqa* soaring overhead.
Credit: Artwork by Davide Bonadonna
License: CC-BY 4.0

Original source:

Ibrahim N, Sereno PC, Varricchio DJ, Martill DM, Dutheil DB, Unwin DM, Baidder L, Larsson HCE, Zouhri S, Kaoukaya A (2020) Geology and paleontology of the Upper Cretaceous Kem Kem Group of eastern Morocco. ZooKeys 928: 1-216. https://doi.org/10.3897/zookeys.928.47517

Contacts:

Prof. Paul Sereno
Email: dinosaur@uchicago.edu

Dr. Nizar Ibrahim
Email: ibrahini@udmercy.edu

“Oldest bamboo” fossil from Eocene Patagonia turns out to be a conifer

A recent examination revealed that Chusquea oxyphylla, a fossilised leafy branch from the early Eocene in Patagonia, which has been widely cited as the oldest bamboo fossil and as evidence for a Gondwanan origin of bamboos is actually a conifer. The results of the finding are published in the open-access journal Phytokeys.

A fossilised leafy branch from the early Eocene in Patagonia described in 1941 is still often cited as the oldest bamboo fossil and the main fossil evidence for a Gondwanan origin of bamboos. However, a recent examination by Dr. Peter Wilf from Pennsylvania State University revealed the real nature of Chusquea oxyphylla. The recent findings, published in the paper in the open-access journal Phytokeys, show that it is actually a conifer.

The corrected identification is significant because the fossil in question was the only bamboo macrofossil still considered from the ancient southern supercontinent of Gondwana. The oldest microfossil evidence for bamboo in the Northern Hemisphere belongs to the Middle Eocene, while other South American fossils are not older than Pliocene.

Over the last decades, some authors have doubted whether the Patagonian fossil was really a bamboo or even a grass species at all. But despite its general significance, modern-day re-examinations of the original specimen were never published. Most scientists referring to it had a chance to study only a photograph found in the original publication from 1941 by the famous Argentine botanists Joaquín Frenguelli and Lorenzo Parodi.

In his recent study of the holotype specimen at Museo de La Plata, Argentina, Dr. Peter Wilf revealed that the fossil does not resemble members of the Chusquea genus or any other bamboo.

“There is no evidence of bamboo-type nodes, sheaths or ligules. Areas that may resemble any bamboo features consist only of the broken departure points of leaf bases diverging from the twig. The decurrent, extensively clasping leaves are quite unlike the characteristically pseudopetiolate leaves of bamboos, and the heterofacially twisted free-leaf bases do not occur in any bamboo or grass,” wrote Dr. Wilf.

Instead, Wilf linked the holotype to the recently described fossils of the conifer genus Retrophyllum from the same fossil site, the prolific Laguna del Hunco fossil lake-beds in Chubut Province, Argentina. It matches precisely the distichous fossil foliage form of Retrophyllum spiralifolium, which was described based on a large set of data – a suite of 82 specimens collected from both Laguna del Hunco and the early middle Eocene Río Pichileufú site in Río Negro Province.

Retrophyllum is a genus of six living species of rainforest conifers. Its habitat lies in both the Neotropics and the tropical West Pacific.

The gathered evidence firmly confirms that Chusquea oxyphylla has nothing in common with bamboos. Thus, it requires renaming. Preserving the priority of the older name, Wilf combined Chusquea oxyphylla and Retrophyllum spiralifolium into Retrophyllum oxyphyllum.

The exclusion of a living New World bamboo genus from the overall floral list for Eocene Patagonia weakens the New World biogeographic signal of the late-Gondwanan vegetation of South America, which already showed much stronger links to living floras of the tropical West Pacific.

“The strongest New World signal remaining in Eocene Patagonia based on well-described macrofossils comes from fossil fruits of Physalis (a genus of flowering plants including tomatillos and ground cherries), which is an entirely American genus,” concludes Dr. Wilf.

Original source:
Wilf P (2020) Eocene “Chusquea” fossil from Patagonia is a conifer, not a bamboo. PhytoKeys 139: 77-89.
https://doi.org/10.3897/phytokeys.139.48717

The ‘Star dust’ wasp is a new extinct species named after David Bowie’s alter ego

During her study on fossil insects of the order Hymenoptera at China’s Capitol Normal University, student Longfeng Li visited the Smithsonian National Museum of Natural History, Washington, carrying two unidentified wasp specimens that were exceptionally well-preserved in Burmese amber. This type of fossilized tree resin is known for the quality of the fossil specimens which can be preserved inside it. Being 100 million years old, they provide an incredible view into the past.

The subsequent analysis of the specimens revealed that both represent species new to science. Furthermore, one of the wasps showed such amazing similarities to a modern group of wasps that it was placed in a currently existing genus, Archaeoteleiawhich has long been considered as an ancient lineage. The species are described in a study published in the open access Journal of Hymenoptera Research.

However, Archaeoteleia has changed since the times when the ancient wasp got stuck on fresh tree resin. The authors note that “a novice might not recognize the characters that unite the fossil with extant species”. For instance, the modern wasp species of the genus show visibly longer antennal segments and a different number of teeth on the mandible when compared to the fossil. In turn, the description of the new extinct species enhances the knowledge about living species by highlighting anatomical structures shared by all species within the genus.

This fossil wasp with living relatives received quite a curious name, Archaeoteleia astropulvis. The species name, astropulvis, translates from Latin to ‘star dust’. The discoverers chose the name to refer to both “the ancient source of the atoms that form our planet and its inhabitants”, as well as to commemorate the late David Bowie’s alter ego – Ziggy Stardust.

Unlike the Star dust wasp, the second new species belongs to a genus (Proteroscelio) known exclusively from Cretaceous fossils. Likewise, it is a tiny insect, measuring less than 2mm in length. It also plays an important role in taxonomy by expanding the anatomical diversity known from this extinct genus.

The authors conclude that their discovery, especially the Star dust wasp and its placement in an extant genus, where it is the only fossil species, “exemplifies the importance of understanding the extant fauna of a taxon to interpret fossils”.

“Such union of fossil and extant morphologies is especially illuminating and requires examination of both kinds of specimens,” they add.

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Original source:

Talamas EJ, Johnson NF, Buffington ML, Dong R (2016) Archaeoteleia Masner in the Cretaceous and a new species of Proteroscelio Brues (Hymenoptera, Platygastroidea). In: Talamas EJ, Buffington ML (Eds) Advances in the Systematics of Platygastroidea. Journal of Hymenoptera Research 56: 241-261. https://doi.org/10.3897/jhr.56.10388