A historical exhibition on the track of giants of the Upper Jurassic

Tendaguru Expedition
From 1909 to 1913 one of the most famous dinosaur expeditions took museum scientists, led by the palaeontologists Werner Janensch and Edwin Hennig, to the Tendaguru hill in today's Tanzania. This place is one of the largest dinosaur deposits in the world. Alongside a number of unique finds, the biggest almost complete dinosaur skeleton ever, Brachiosaurus brancai, was discovered. It is the centrepiece of our spectacular exhibition, which shows dinosaurs in the context of fossil plants and animals, that shared a habitat in East Africa 150 million years ago.
Finding site
The Tendaguru site, named for a small local mountain, is located about 60 kilometers from the ocean. It is one of the richest and most important fossil deposits in the entire world. More than a century ago, a scientific expedition set out from Museum für Naturkunde Berlin, to return four years later with more than 230 tons of fossils. A selection of some of the most impressive finds is on display in the museum's dinosaur hall.

The discovery of the important fossil beds near the base of Mt. Tendaguru in East Africa was one of the greatest moments in paleontology. When the scientists of the Berlin Museum of Natural History’s Institute for Geology and Paleontology arrived at the site in April of 1909, they found areas that were seemingly covered in fossilized dinosaur bones, washed out of the earth by a recent rainstorm. Without this accidental erosion, the site might never have been discovered three years earlier.

Wilhelm von Branca, director of the Geological-Paleontological Institute at Museum für Naturkunde Berlin, successfully purchased funds for an exhibition. Curator Werner Janensch and his assistent Edwin Hennig formed the first team travelling to Africa.

Letter from Werner Janensch

A plethora of fossils awaited expedition director Werner Janensch and his team. They needed a large amount of helpers to excavate and preserve what they found: at times, as many as 500 local workers were employed in the field.

The workers were educated in diverse tasks relevant for the excavation. Measured by the standards of that time, they were rewarded appropriately.

Though some bones were lying loose on the surface, many were still encased in solid rock and had to be carefully removed with hammers, chisels, and knives.

Brachiosaurus' giant bones were among the first found by the Berlin Tendaguru expedition of 1909, but it took more than two years before the last fossilized bone was chiseled out of the rock and prepared for shipment.
With nearly every report, Janensch could send news about large bones and even nearly complete skeletons to Berlin.

African labourers made transport cases from bamboo and sections of tree trunks. Wrapped in a protective layer of clay and plaster, fossils were placed inside and shipped back to Berlin.

Smaller finds were packed into the hard husks of the fruit of the baobab tree. Even empty tin cans were pressed into service.

Local labourers carried the transport cases by foot over a distance of 60 km to the harbour of Lindi. Therefrom the findings started a journey to the museum in Berlin.

For over 4 years a various range of fossils from dinosaurs were found at Tendaguru. These include masses of bones from the herbivore Kentrosaurus aethiopicus and the small Dysalatosaurus lettowvorbecki, a partial skeleton of the carnivore Elaphrosaurus bambergi as well as bones and teeth from at least three other predatory dinosaurs. The most diverse findings were the bones of sauropods, the largest terrestrial vertebrates that ever lived. In Tendaguru they were represented by the famous longicollous Giraffatitan brancai, two smaller species of Dicraeosaurus hansemanni und Dicraeosaurus sattleri, the Titanosaurs Janenschia robusta and Australodocus bohetii, the primary sauropod Tendaguria tanzaniensis and the slender long-neck Tornieria africana. Nowhere else in the world a repository with so many different dinosaur species in such a small space is known, yet.

Back in Berlin
After the arrival in Berlin mainly attractive and scientifical valuable fossils were prepared for the exhibition. One by one the most impressive dinosaur skeletons found their place in the museum's remodeled atrium.

Brachiosaurus, today Giraffatitan brancai, 1937

Brachiosaurus - The Giant
Ever since the Tendaguru-expedition, scientists have been trying to unlock the secrets of this giant dinosaur, which roamed the earth 150 million years ago. Thanks to advances in scientific methods and cooperation between specialists from different areas, it’s still teaching us new things a century after its discovery. That’s why the skeleton when remounted in 2007 looks very different from the version on display for almost 60 years (shown here).

The legs are no longer bent away from the body, but stand straight directly beneath; structural engineers calculated that Brachiosaurus would otherwise have never been able to carry its massive weight. Its swanlike neck is held closer to vertical, as this would have placed the least stress on the delicate neck vertebrae, and its tail no longer drags along the floor, but is raised high in the air, acting as a counterweight. And Brachiosaurus has lost weight: Earlier estimates were that it weighed around 70 tons, but new research puts that figure at just 38 tons. Some scientists think even that might be exaggerated by half.

When laborers working on the Tendaguru excavation unearthed this well-preserved skull a century ago, they caused a scientific sensation.

Particularly noticeable are the two large, arched nasal passage openings near the top of the skull. Directly below the nasal openings, and most easily visible from the side, are the are the antorbital fenestrae, so called because they lie directly in front of the eye sockets, or orbits. The antoribital fenestra is a characteristic trait of dinosaurs; it included an aerostat and served weight reduction. Next to the eye sockets, you see the temporal fenestrae, through which which bundles of powerful muscle fibers could pass from the inside to the outer surface of the skull, where greater surface area provided a more solid attachment point. These muscles were only used to open and close the jaws: the peg-like, inwardly inclined teeth of Brachiosaurus were not suited for chewing. Instead, it tore twigs and branches from trees and swallowed them whole.

With its huge size, Brachiosaurus continues to puzzle modern scientists. Soft tissues such as internal organs almost never survive fossilization, so it’s difficult to be sure, but it’s assumed that this sauropod would have been almost constantly eating to meet its enormous energy needs. Its peg-shaped teeth weren’t designed for chewing, so it must have torn young branches from the forest canopy and swallowed them whole, perhaps as much as a ton a day. It would have had an accordingly large stomach. Nevertheless the stomach wasn't functioning like a fermentation tank, but the sauropods' digestive system was longer and included sort of a hindgut, similar to today's horses digestion. Nutriment had a long dwelling time in the stomach until excretion, so the nutrient levels of available plants back then was effectively used. This also explains the giant, barrel-shaped body of sauropods.

Jurassic Dinosaurs - Parade of Titans
Dinosaurs dominated the Tendaguru ecosystem. Most of them were herbivores and ate coniferous trees, farns, and other plants. Dinosaur predators hunted their plant-eating relatives. 

One of the most fascinating finds of the German Tendaguru expedition is the almost complete skeleton of Dicraeosaurus hansemanni, with ist 10 m total length among the smallest sauropods. These sauropods are among the largest animals that ever lived on land.

Its short neck also sets it apart from most other sauropods. The spinal processes on the vertebrae of the neck are special as they are tilted to the front, so that each of them interlocks with the preceding vertebra.

Kentrosaurus is not a member of the sauropod group. Rather, it is a stegosaurid, one of a group of quadrupedal herbivores that sported bony spikes and plates along their spines. The stegosaurids belong to the order Ornithischia, or the „bird-hipped“ dinosaurs. At first glance Kentrosaurus doesn’t look to have much in common with the birds, but take a closer look at its pelvis. Do you see the two long bones that extend downward between the rear legs? This arrangment of the pubic bone and the ischium is also found in birds, thus the descriptive term „bird-hipped“. By contrast, the three sauropods you see here belong to the order Saurischia, or „lizard-hipped“ dinosaurs. Their pubic bones – the right-hand one of the two pelvic bones – point slightly forward.

Dysalotosaurus is the smallest herbivore dinosaur found in Tendaguru.
The strong build and the length of its hind legs indicate that it was a swift runner and walking upright. As dozens of skeletons were found in a single excavation site, scientists think that the animals lived in herds. Protection in the group could have been an important survival strategy. It would have been difficult for raptors to isolate their prey from the herd.

Predatory dinosaurs
Elaphrosaurus bambergi is the only well-preserved predatory dinosaur of the Tendaguru. Of other species, only individual bones or teeth were found.

This slender predator shows sharp teeth specialized for catching and holding prey. Its pelvis and back legs are also designed for hunting: notice the relatively short thighs and the long bones of the lower legs and metatarsals, which served as a lever enabling the leg muscles to exert greater force. Can you see the protrusion at the rear of the thighbone? This was the attachment point for a powerful muscle that ran to the tail, which helped to pull back the leg and improved acceleration. The narrow, three-toed foot – the first toe is a dew-claw – is built for speed. It’s thought that Elaphrosaurus may have been able to run as fast as 70 kilometers per hour.

Allosaurs were the largest carnivores of their time. They were members of the theropod group of dinosaurs. Another member of that group, millions of years later during the Cretaceous period, is Tyrannosaurus rex.

The Allosaurus skeleton displayed here is only a cast; the original was found in North America. However, discoveries of individual bones and teeth prove that large predatory dinosaurs related to this one roamed Tendaguru in East Africa during the same period.

Compared to the rest of its skeleton, it’s skull was extremely large and powerfully built – a necessity for the attachment of its powerful jaw muscles. Thanks to its efficient shape and the large openings in the skull, though, it still wasn’t excessively heavy.

The Diplodocus carnegii shown here is a copy of a famous skeleton found in North America in 1899. The original stands in the Carnegie Museum in Pittsburgh in the USA. Diplodocus quickly obtained celebrity status when Andrew Carnegie, millionaire and founder of the Pittsburgh museum, commissioned eleven copies to be donated to natural history museums in Europe and South America.

Diplodocus lived at about the same time, and is a close relative of another sauropod whose remains were found in East Africa, Tornieria africana. Only a few bones of Tornieria have been found, though, so Diplodocus serves here as something of a stand-in.

Our Jurascope films aim to reflect current scientific consensus, new discoveries or newly developed research methods are however constantly adding to or changing what we know.

The Environment at Tendaguru
The wavy line represents the surface of the ocean. Beneath it are found the various ocean dwellers – fish, molluscs, and crabs. The line at the bottom, the sea floor, slopes sharply upward toward the right and forms a large sandbank covered in corals and thick-shelled oysters. This unusual form of reef, known as an apron reef, was typical for the Tendaguru region 150 million years ago. It separated the shallow water of the lagoon, on the left, from the open sea.

The Jurassic oceans were populated by a multitude of vertebrates such as sharks, rays, primitive bony fishes with strong scales (ganoid fish), modern types of bony fishes as well as reptiles adapted to life in the ocean.

Displayed on the glass wall before you is an ancient fossilized shark, Hybodus fraasi, with its characteristic dorsal spines. Such detailed shark fossils are very unusual. Sharks have skeletons made of cartilage, which decomposes much more quickly than bone. Most of our information about early sharks comes from teeth and sharp spines, some of which were also excavated at Tendaguru. Some of these are individual teeth from prehistoric sharks, while others are from an ancestor of today’s rays, another group of cartilaginous fish.

Not all marine animals, however, seem to have flourished in the Tendaguru environment. Only a few fossilised ammonites and brachiopods were found in Eastern Africa, common as they were in other locations. Bivalve molluscs (oysters, mussels, clams, etc.) and snails, by contrast, seemed to have coped very well with their variable habitat and are often found as fossils at Tendaguru.

The first pterosaurs appeared in the skies more than 215 million years ago. Their quite effective wings were covered in skin. Despite what you might think, they weren’t flying dinosaurs; but both they and the dinosaurs were subgroups of the larger group of archosaurs. Pterosaurs aren’t the ancestors of modern birds, which use feathers, rather than membranes, to fly. Instead the active birds' flight, as we know it today, evolved from advanced, feathered predatory dinosaurs like Microraptor or Archaeopteryx, who were able to flutter.

As far as we know, the first creatures on Earth to fly were insects – the first ones took to the sky more than 300 million years ago. Such well-preserved finds are rare; the delicate details of wings and other insect parts only survive in very fine-grained sediments. That’s why the speciments you see here are from the limestone beds of Solnhofen in Germany, rather than Tendaguru, where the conditions for preservation were less than ideal.

Few larger pieces of plant remains were found at Tendaguru itself, where environmental conditions weren’t favorable to the survival of such delicate fossils. The cycad frond and conifer branch shown here were found in Europe, but pollen and spores discovered at Tendaguru imply that similar plants once flourished in East Africa as well. The pollen and spores were probably carried to the Tendaguru region from farther inland.

Thanks to the warm, dry climate, huge, species-rich coniferous forests flourished, much more biologically diverse than today’s. There were also cycads and ferns, horsetails, and mosses. Fossilized traces of this lush flora are found all over the Tendaguru region, carried there by wind and water.

Research
Brachiosaurus and several other finds from the Tendaguru expedition remain the focus of scientific interest at Museum für Naturkunde. Our knowledge of these extraordinary creatures is continuously expanding, due to new research methods and cooperation between different fields of science.

A new scientific name was given to Brachiosaurus in 2009, when differences in the shape, size and proportions of the bones led to the distinction between a North American and an African Brachiosaurus genus. Thus, Brachiosaurus brancai became Giraffatitan brancai. This is now the scientifically recognised name used by researchers.

Paleontologists Florian Witzmann and Oliver Hampe from Museum für Naturkunde Berlin in cooperation with scientists from the Charité and the Helmholtz-Centre for Materials made a sensational discovery: They detected the oldest viral structures to date on a more than 150 million years old vortex from Dysalatosaurus lettowvorbecki.

The herbivore dinosaur from Tendaguru was suffering from Paget, a viral bone disease, only attested to humans and primates so far.

In 2011 a team of researchers from Museum für Naturkunde investigated the skull of Dysalatosaurus with computertomographic methods. The dinosaur had an enhanced ability to hear, comparable to recent birds or crocodiles. Supposedly Dysalatosaurus was a prefered prey for predatory dinosaurs, so he used his sense of hearing to escape like many herbivore mammals do nowadays.

Some boxes still haven’t been opened; a century later, the paleontologists of the museum are still unlocking the secrets of Tendaguru.

Credits: Story

Images: Antje Dittmann, Hwa Ja Götz, Carola Radke, Historische Arbeitsstelle (Museum für Naturkunde Berlin)

© naturkundemuseum.berlin

Credits: All media
The story featured may in some cases have been created by an independent third party and may not always represent the views of the institutions, listed below, who have supplied the content.
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