It is the end of this year’s excavation season for Bromacker project team members. The excavations at the world-famous Bromacker fossil site in Thuringia (Germany) have been a success. A layer of fossils bones, small skeletons and an ash layer suitable for age determination promise new insights into the 290-million-year-old ecosystem of the Bromacker locality.  In just eighteen days, over fourteen hundred volunteers participated in the field work. Congratulations to everyone involved in this exciting project.

Field team members working on the Bromacker project (June 2025). Picture credit: Bromacker Projektteam.

Picture credit: Bromacker Projektteam

A Successful Conclusion to this Year’s Bromacker Project Field Work

The Bromacker location is one of the world’s most significant fossil sites documenting an Early Permian terrestrial ecosystem. An international research team consisting of palaeontology and geology experts, including students, technical staff and science communicators, has been excavating at the Bromacker locality for several weeks every year since 2020. The Museum für Naturkunde Berlin, the Friedrich Schiller University Jena, the Friedenstein Foundation Gotha, and the UNESCO Global Geopark Thuringia Inselsberg – Drei Gleichen are involved in the project.

To read an earlier blog post about the discovery of fossilised skin impressions at the site: Early Synapsids and Skin Impressions.

Approximately fifty researchers from six countries took part in this year’s excavation work. Over two hundred and fifty fossils were recovered from the site.

Project and excavation manager Prof Jörg Fröbisch (Museum für Naturkunde Berlin) is extremely pleased with the new finds.

He commented:

“This year’s excavation at Bromacker was once again a huge success and has revealed completely new aspects. This again includes numerous and varied finds of prehistoric bones, trace fossils, invertebrates and plants. The discovery of an extensive bone layer and two small skeletons, possibly from early reptiles, is particularly exciting. We have also examined one of the massive sandstone beds for the first time and discovered vertebrate burrow systems and plant remains. The identification of an ash layer is also spectacular, which we hope will allow us to determine the exact age of the find layers for the first time.”

The Free State of Thuringia is continuing the funding until the middle of 2026. With the continuation of excavations, preparation, collection management and various educational programmes and communication formats for the general public, the future of the UNESCO World Heritage status of the Thuringia Inselsberg – Drei Gleichen Geopark is secured.

Dr Tom Hübner (Friedenstein Foundation Gotha), is delighted with this news.

Dr Hübner added:

“The new commitment of the state of Thuringia to the Bromacker is of particular significance and underlines the importance of this unique fossil site for the region and far beyond. We are particularly pleased that the recently approved funding will make it possible to carry out another excavation next year.”

Everything Dinosaur acknowledges the assistance of a media release from the Museum für Naturkunde Berlin in the compilation of this article.

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A new species of tyrannosauroid described by scientists as a “missing link” sheds new light on the evolution of Late Cretaceous tyrannosaurs.  The dinosaur, named Khankhuuluu mongoliensis represents a transitional form between the small, gracile early tyrannosauroids and the giant, bone-crushing, apex predators such as Daspletosaurus and Tyrannosaurus rex.  The large tyrannosaurs from the end of the Cretaceous (Campanian and Maastrichtian) have been intensively studied.  However, the evolutionary origins of these super-sized theropods remains poorly understood.  It is known that these dinosaurs evolved from much smaller ancestors.  The discovery of Khankhuuluu (pronounced: khan-KOO-loo), helps palaeontologists to fill in a gap between these ancestral forms and the Late Cretaceous giants.

Khankhuuluu mongoliensis represents a transitional form between small tyrannosauroids of the early Late Cretaceous and the giants of Campanian and Maastrichtian. Yes, I know Maastrichtian is not correct in the diagram :). Picture credit: Everything Dinosaur.

Picture credit: Everything Dinosaur

Khankhuuluu mongoliensis

A team of researchers led by scientists from the University of Calgary (Alberta) have described a new species of tyrannosauroid from the Upper Cretaceous Bayanshiree Formation of southeastern Mongolia. University of Calgary PhD student Jared Voris found unique autapomorphies in two fossil specimens that had been assigned to the tyrannosauroid Alectrosaurus. For example, an air cavity was identified in the nasal bone and the student found other traits that indicate this dinosaur was evolving the skull anatomy that would generate immense bite forces.

Phylogenetic analysis suggests that K. mongoliensis sits just outside the Eutyrannosauria. This is the clade which contains giant tyrannosaurs such as Gorgosaurus, Lythronax, Tarbosaurus and T. rex as well as, smaller more lightly built predators.

The Eutyrannosauria is split into two tribes:

• Alioramini (for example Qianzhousaurus and Alioramus): smaller, slender, shallow-skulled forms.
• Tyrannosaurini (for example Tyrannosaurus rex): massive, deep-skulled forms.

Khankhuuluu and the Alioramini both share certain traits. They are lightly built, have long hind limbs and shallow skulls.  These characteristics are seen in juvenile specimens of the giant tyrannosaurs such as Tarbosaurus and T. rex. These traits evolved due to heterochrony, meaning changes in the timing of growth during evolution.  Writing in the journal “Nature” the research team which included Professor Darla Zelenitsky (University of Calgary) suggest that accelerated growth led to the evolution of the giant forms of tyrannosaur (peramorphosis). In contrast, the Alioramini retained juvenile traits into adulthood (paedomorphosis).  This explains, their smaller size and gracile build.

It is postulated that the different body types of the Alioramini and Tyrannosaurini likely helped them live side by side in Asia by filling different ecological roles.

The Prince of Dragons

The fossils were discovered in the 1970s at the Baishin-Tsav locality (Bayanshiree Formation). The strata are believed to have been laid down in the Turonian to Santonian faunal stages of the Late Cretaceous. The fossils of Khankhuuluu mongoliensis are thought to be approximately 86 million years old. Khankhuuluu is estimated to have weighed around 750 kilograms and measured around four metres in length.

The dinosaur’s name translates as “Mongolia’s Prince of Dragons”.  It hints that this theropod was a prince that led to the evolution of the “tyrant kings”.

The Everything Dinosaur blog has documented numerous articles about new discoveries leading to the erection of new Tyrannosauroidea taxa.  Most of these dinosaurs were considerably smaller than Khankhuuluu.

To read about the discovery of a small-bodied tyrannosauroid from southern Laramidia: Suskityrannus – The Shape of Things to Come.

The contemporary Timurlengia from Uzbekistan: New Dinosaur Sheds Light on How Tyrannosaurs Got Big.

Moros intrepidus, a member of the Superfamily Tyrannosauroidea from Utah: Moros – A Diminutive Tyrannosauroid.

Alioramini Not a Basal Lineage

Previously, phylogenetic analysis had relied too much on immature specimens, and this led to the assumption that the Alioramini were a primitive, early diverging group. However, the researchers postulate that the Alioramini were not basal, but more derived representing theropods that retained immature features into adulthood.

Furthermore, the study reveals that Asian tyrannosauroids (similar to Khankhuuluu) dispersed to North America. They gave rise to the Eutyrannosauria. The Eutyrannosauria diversified and remained exclusively in North America until a single dispersal to Asia in the latest Cretaceous that established the Alioramini and Tyrannosaurini tribes.

The scientific paper: “A new Mongolian tyrannosauroid and the evolution of Eutyrannosauria” by Jared T. Voris, Darla K. Zelenitsky, Yoshitsugu Kobayashi, Sean P. Modesto, François Therrien, Hiroki Tsutsumi, Tsogtbaatar Chinzorig and Khishigjav Tsogtbaatar published in Nature.

The Everything Dinosaur website: Dinosaur Models and Toys.

Scientists have revealed the last meal of an Australian herbivorous dinosaur that lived ninety-five million years ago.  Researchers writing in the journal “Current Biology” report on the discovery of Diamantinasaurus matildae stomach contents.  This remarkable discovery is the first time that sauropod stomach contents have been identified.  The analysis of the plant remains suggests bulk feeding and multi-level browsing.  The Diamantinasaurus nicknamed “Judy” was not fussy when it came to food.  Plants eaten by Diamantinasaurus include conifers, seed ferns and angiosperms. In addition to the fossilised stomach contents, the scientists also examined mineralised skin found with the specimen. This revealed a pattern of polygonal (often hexagonal) non-overlapping scales, a characteristic commonly seen in other sauropods.

A life reconstruction of the Australian titanosaur Diamantinasaurus matildae. Picture credit: Travis Tischler.

Picture credit: Travis Tischler

Diamantinasaurus matildae Stomach Contents

Sauropods were abundant and diverse throughout the Jurassic and Cretaceous.  The Sauropoda include the largest terrestrial animals known to science.  Studies of teeth suggest these dinosaurs were herbivorous.  However, our knowledge of their diet is based on indirect evidence such as coprolites (dung).  Furthermore, no fossilised gut contents (cololites) were known.  Intriguingly, this all changes with the publication of a remarkable study that describes Diamantinasaurus matildae stomach contents.

Subadult Diamantinasaurus matildae stomach contents. Undigested leaves can be clearly observed in the cololite. Picture credit: Australian Age of Dinosaurs.

Picture credit: Australian Age of Dinosaurs

The fossil material was collected from Winton Formation exposures (Queensland, Australia).  The cololite was located in the abdominal region and closely associated with a layer of mineralised skin.  Detailed analysis of the cololite reveals the plant material eaten.  Conifer pinnules, angiosperm leaves, and seed-fern fruiting bodies are preserved.  In addition, chemical biomarkers are identified consistent with angiosperms and gymnosperms.

This Diamantinasaurus matildae cololite provides the first direct, empirical evidence in sauropods of herbivory, demonstrating generalist feeding, low- to high-level browsing, and minimal oral processing of food.  It seems that these animals were not fussy what plant material they consumed.  They did not chew or grind up their food, relying on their enormous guts to digest the plant material.  Food may have persisted in their guts for a fortnight or more before being excreted.

Australian Age of Dinosaurs Collection Manager Mackenzie Enchelmaier (co-author of the study) highlighting the Diamantinasaurus gut contents. Picture credit: Australian Age of Dinosaurs.

Picture credit: Australian Age of Dinosaurs

The study marks the first use of molecular techniques to identify sauropod stomach contents.

Sauropods Feeding at a Range of Heights

The research was led by Dr Stephen Poropat (Curtin University, Perth, Western Australia).  The Diamantinasaurus specimen, originally found in 2017 has provided unprecedented detail on the feeding habits and diets of the Sauropoda.

The first direct, empirical evidence in sauropods of herbivory, demonstrating generalist feeding, low- to high-level browsing, and minimal oral processing of food. Picture credit: Australian Age of Dinosaurs.

Picture credit: Australian Age of Dinosaurs

To read Everything Dinosaur’s blog post from 2009 about the discovery of Diamantinasaurus: A Trio of New Dinosaurs from Australia.

Dr Poropat stated:

“The specific plants that they ate, and the height above ground at which they fed, have remained unknown – until now. The stomach contents we found belonged to a 12-metre-long, subadult sauropod that was still growing at the time of its death. Our findings show that at least some species of subadult sauropods were able to feed at a range of heights above ground level, and consequently were equipped to deal with environmental and vegetation changes throughout the Jurassic and Cretaceous periods.”

Co-author of the study, John Curtin Distinguished Professor Kliti Grice added:

“By using advanced organic geochemical techniques, we were able to confirm the presence of both angiosperms and gymnosperms in the diet of this sauropod. This unique approach provided molecular evidence of the plants that sauropods consumed.”

Mineralised Skin

Furthermore, this amazing titanosaur fossil specimen revealed details of its skin texture. The researchers identified a pattern of five-sided (often hexagonal), non-overlapping scales. This type of integumentary covering has been found in other sauropod specimens. The scales measure between seven and thirteen mm in diameter.   Each scale is covered in small bumps (papillae).  Their appearance is consistent with other known sauropod skin fossils.

Mineralised skin found with the Diamantinasaurus specimen known as Judy reveals polygonal (often hexagonal) scales. Picture credit: Australian Age of Dinosaurs.

Picture credit: Australian Age of Dinosaurs

The Diamantinasaurus matildae stomach contents and mineralised skin were preserved alongside yet-to-be-published body fossils of the subadult.  The fossils are housed at the Australian Age of Dinosaurs Museum. These fossils will form a key part of the Australia Through Time exhibition in the Museum’s future multi-million-dollar facility.

The longevity of the clade Sauropoda was underpinned by the persistence through time of generalist feeders like Diamantinasaurus matildae that were capable of feeding at a range of heights on a wide variety of different plant species.

Everything Dinosaur acknowledges the assistance of a media release from the Australian Age of Dinosaurs in the compilation of this article.

The scientific paper: “Fossilized gut contents elucidate the feeding habits of sauropod dinosaurs” by Stephen F. Poropat, Anne-Marie P. Tosolini, Samantha L. Beeston, Mackenzie J. Enchelmaier, Adele H. Pentland, Philip D. Mannion, Paul Upchurch, Karen Chin, Vera A. Korasidis, Phil R. Bell, Nathan J. Enriquez, Alex I. Holman, Luke M. Brosnan, Amy L. Elson, Madison Tripp, Alan G. Scarlett, Belinda Gode, Robert H. C. Madden, William D. A. Rickard, Joseph J. Bevitt, Travis R. Tischler, Tayla L. M. Croxford, Trish Sloan, David A. Elliott and Kliti Grice published in Current Biology.

For models and replicas of dinosaurs and other prehistoric animals: Dinosaur Models.