Brachiosaurus brancai Janensch, 1914

Stoecker, Holger & Ohl, Michael, 2024, Taxonomies at Tendaguru: How the Berlin Dinosaurs Got Their Names, Deconstructing Dinosaurs: The History of the German Tendaguru Expedition and Its Finds, 1906 – 2023, Brill, pp. 233-254 : 1

Brachiosaurus brancai Janensch, 1914

Giraffatitan brancai ( Taylor, 2009)

Brachiosaurus fraasi Janensch, 1914

The genus Brachiosaurus was introduced in 1903 by the Chicago-based paleontologist Elmar Samuel Riggs to describe finds discovered in western Colorado ( B. altithorax ). The name alludes to the enormous size and unusual length of the dinosaur’s upper arm bones (humeri). 38 It derives from the Greek words βραΧίων / brachíōn (“arm”) and σαυρα / saúra, and roughly means “arm lizard.”

Brachiosaurus brancai was not only the largest dinosaur to be excavated at Tendaguru, it was also among the first of the expedition’s specimens to be rigorously studied and described as a new species. Werner Janensch dedicated the specific name “with gratitude and the greatest admiration and respect” to Wilhelm von Branca, the geologist and paleontologist who headed the Geological and Paleontological Institute and Museum from 1899 to 1917, 39 and described him as “[the man] to whom we owe the launching and organization of the entire expedition.” 40

Shortly after Janensch’s species description was published, however, doubts were expressed regarding his referral of the species to the genus Brachiosaurus , and these doubts were never entirely dispelled. 41 Even so, it took almost one hundred years before the specimen was reclassified. In 2009, British paleontologist Michael P. Taylor performed a comparative analysis of the North American Brachiosaurus altithorax (the type species for Brachiosaurus ) and the East African B. brancai , and came to two conclusions: that they belonged to different genera and that B. brancai should be placed in the genus Giraffatitan , as proposed by Gregory S. Paul in 1988. 42 This Latinized genus name alludes to the dinosaur’s giraffe-like form and enormous—titanic—size. 43

Interestingly, although there is now no question that the dinosaur’s proper name is Giraffatitan brancai , the museum’s exhibition texts and its publications continue to refer to it as Brachiosaurus brancai , as do the general public. 44 The use of this taxonomically incorrect name is a tribute to the immense and enduring popularity of the Museum für Naturkunde’s star exhibit. Its old name, now obsolete, has been associated with the specimen for so long that it has taken on something of the character of a common name, and it continues to draw the public in droves. In 1914, Janensch described an additional species based on fossil remains found in a neighboring stratum and named it Brachiosaurus fraasi . This was the second time that he named a species after a natural scientist who played a critical role in getting the Tendaguru Expedition off the ground. That scientist was Eberhard Fraas, the first paleontologist to visit the site and conduct a brief but productive dig there in September 1907. Janensch wrote: “I am naming this species after Prof. Dr. E. Fraas, who to his great credit and under the most difficult of circumstances successfully conducted the first scientific study of dinosaur finds at Tendaguru.” 45 By 1929, however, Janensch himself suspected that B. fraasi was synonymous with B. brancai , 46 and B. fraasi has not been used since.