Tendaguru Excavations: The German Dinosaur Dig in Tanzania

The Tendaguru excavations were a series of large dinosaur digs at Tendaguru Hill in what is now south-eastern Tanzania, carried out by an expedition of Berlin’s Museum für Naturkunde from 1909 to 1913, when the region was the German colony of German East Africa. Hundreds of African labourers dug out and carried to the coast more than 200 tonnes of fossils. The finds included the gigantic sauropod now called Giraffatitan, whose mounted skeleton in Berlin remains one of the tallest dinosaur displays in the world.

Background: discovery in a colonial setting

Germany had claimed the mainland of present-day Tanzania in the 1880s and 1890s, part of the Scramble for Africa. The south-east of the colony had just experienced the Maji Maji Rebellion of 1905–1907, a large uprising against German rule that was suppressed with great loss of life, much of it from famine.

In 1906 Bernhard Wilhelm Sattler, an engineer working for a mining company near Lindi, noticed huge bones weathering out of the ground near Tendaguru Hill. In 1907 the Stuttgart palaeontologist Eberhard Fraas visited the site, collected material and confirmed that it held large dinosaurs.

News of the find reached Berlin, where the Museum für Naturkunde was eager to rival the American museums that had dominated dinosaur discoveries since the Bone Wars. A committee raised funds through donations from private patrons, scientific bodies and public authorities to send a major expedition.

The German expedition, 1909–1913

The expedition was led in the field by the palaeontologists Werner Janensch and Edwin Hennig, who arrived in 1909. Later seasons were directed by Hans Reck, who worked at Tendaguru in 1912 and 1913 with his wife Ina Reck. The scientists were few; the work force was large.

Local African workers were recruited to dig, with numbers growing from about 170 in the first season to around 500 at the peak. Many brought their families, so the camp became a sizeable settlement with its own huts, food supplies and water arrangements. Women and children also took part, for example by carrying water and smaller loads.

Excavation was done mostly with hand tools. Bones were often fragile and were wrapped in a mixture of plaster or local materials for protection. Because there were no roads or railways, every load was carried on foot to the port of Lindi, a journey of about four days, and then shipped to Germany. Several thousand porter loads were needed over the four years.

What they found

The richest material came from a huge sauropod that Janensch named Brachiosaurus brancai in 1914, after the museum’s director Wilhelm von Branca. Its long forelimbs and raised shoulders gave it a giraffe-like build. In 2009 the palaeontologist Michael Taylor showed that it differed enough from the American Brachiosaurus to be placed in its own genus, Giraffatitan, a name first proposed as a subgenus by Gregory Paul in 1988.

The expedition also found the small plated dinosaur Kentrosaurus, the sauropods Dicraeosaurus and Tornieria, the slender theropod Elaphrosaurus, pterosaurs and many other animals and plants. Altogether at least 225 tonnes of material are commonly said to have been shipped to Berlin.

Giraffatitan was among the largest land animals known at the time. Its front legs were longer than its hind legs, so its back sloped down from the shoulders, and its long neck could probably be held well above the body to reach high vegetation. Length estimates are usually around 22 to 23 metres, while mass estimates have varied widely between studies, many recent ones falling roughly between 20 and 40 tonnes.

Kentrosaurus was a much smaller relative of Stegosaurus, about 4 to 5 metres long, with a double row of plates on its neck and back that turned into long spikes over the hips and tail. Hundreds of its bones were found, making it one of the better known stegosaurs. Dicraeosaurus was a short-necked sauropod, a reminder that not all long-necked dinosaurs browsed high in the trees.

The Berlin skeleton

Preparing the material took decades. Janensch supervised the work and published detailed descriptions over many years. In 1937 the museum unveiled a mounted skeleton of Giraffatitan in its great hall, built mainly from the bones of several individuals with missing parts modelled in plaster.

The museum building was damaged during the Second World War, but the skeleton had been dismantled and the bones largely survived. It was remounted in a revised, more accurate pose in 2007. The mounted skeleton stands about 13.3 metres tall and was recognised by Guinness World Records as the tallest mounted dinosaur skeleton.

After 1913: war and the British excavations

The First World War ended German rule. After 1918 the territory became Tanganyika, administered by Britain under a League of Nations mandate. The British Museum (Natural History) sent its own expedition from 1924 to 1931, led first by William Cutler, who took the young Louis Leakey as an assistant; Cutler died of malaria in 1925. The work continued under later leaders, and many of the experienced African workers from the German period took part again.

Among them was Boheti bin Amrani, a skilled foreman who had worked for the Germans and became a key figure for the British team. His knowledge of the sites and methods was essential, yet, like most African workers, he received little public recognition at the time.

Legacy and debate

Tendaguru is one of the most important Late Jurassic fossil sites anywhere, and its fauna, dating to roughly 155 to 145 million years ago, is often compared with that of the Morrison Formation in North America. The similarities and differences help scientists understand how dinosaurs were distributed across the world before the continents moved further apart.

In recent decades historians have re-examined the excavations as part of colonial history. They stress the role of the African workforce, the colonial conditions under which the work took place, and the fact that almost all the fossils left the country. Tanzanian politicians and scholars have raised the question of whether some material should return, and researchers in Germany and Tanzania have discussed cooperation on the collection and its history.

By the numbers

Timeline

• 1906: Bernhard Wilhelm Sattler notices large fossil bones near Tendaguru Hill.
• 1907: Eberhard Fraas visits the site and collects dinosaur material.
• 1909: Werner Janensch and Edwin Hennig begin the Berlin museum’s excavations.
• 1912–1913: Hans Reck leads the final German seasons.
• 1914: Janensch names Brachiosaurus brancai.
• 1924–1931: The British Museum (Natural History) runs its own Tendaguru expedition.
• 1937: The mounted skeleton is unveiled in Berlin.
• 2007: The Berlin skeleton is remounted in a revised pose.
• 2009: Giraffatitan is confirmed as a separate genus from Brachiosaurus.

Why it matters

Tendaguru produced some of the most spectacular dinosaur fossils ever found in Africa and gave Berlin one of the world’s best known museum displays. It also offers a clear example of how scientific collecting in the colonial era depended on African labour and expertise. Today the story is told both as a landmark in palaeontology and as part of the wider history of colonialism and its legacies.