Field of Science

History of Paleomammology: Ex Africa Semper Aliquid Novum

To celebrate the soccer world championship in a geological manner, the story of an extraordinary naturalists on the tracks of mammal ancestors in an extraordinary land: South Africa:

Robert Broom was born in 1866 in the town of Paisley, Scotland, and after graduating in medicine in 1887 undertook several "world"-trips to satisfy his passion: the search for fossils. Doctor by profession, he devoted himself to several paleontological problems in his long career.


In the first years after completing his degree he became interested in the origin of mammals, and so in 1892 he travelled to Australia, where he studied the fossils and the anatomy of modern marsupials, on which he published important contributions. Broom returned to Scotland in 1896, after some problems with the Australian bureaucracy caused by his passion.
After seeing the fossils of the Karoo region exposed in the British Museum, he decided to visit this region. In 1897 he emigrated to South Africa to study the sediments of the Karoo - a semi-arid highland region in South Africa.

Fig.1. Scheme of the Strata in South Africa, from SCHWARTZ 1912.
The Karoo Supergroup is a 12 km thick succession of sedimentary rocks that accumulated in a large intracratonic retroarc foreland basin in southwestern Gondwana. The strata record 100 million years of almost continuous sediment accumulation from the Permo-Carboniferous (300 Ma) through to the Early Jurassic (190 Ma) under a range of climatic regimes and within several tectonically controlled sub-basins.
Alluvial sediments dominate the succession from the Late Permian onwards. Fossils of synapsid reptiles and early dinosaurs are sufficiently common to be used in a ten-fold biostratigraphic subdivision of these strata. The Permian/ Triassic boundary in the Karoo succession is marked by a major extinction of the herbivorous dicynodonts which co-incides with a rapid change in fluvial facies, evidence of environmental changes that may have caused the tetrapod extinctions in the main Karoo Basin (SMITH 1995).

Broom opened a private ambulatory in a small town, not to far from Cape Town, the capital of South Africa. Always looking for new discoveries, he repeatedly changed his place of residence, and in his spare time went to look for fossils, so in 1903 he discovered the remains of the sauropod Algosaurus.

In the Karoo sequence, ranging in age from the Carboniferous to the Jurassic, he discovered and described various species of therapsids. This important work will result in a nomination as zoology and geology professor at the University of Stellenbosch in Cape Town. He remained there until 1909, when a change of government, and new problems with the management of the University, convinced him to return to London.
For a certain period, he shuttled between New York and South Africa. Only from 1916 onwards Broom devoted himself again mainly to the fossils of Karoo, on which he continued to publish extensively.


Fig.2. Fossils of the stratigraphic succession of the Karoo, from a print of 1909.


In the later years of his life, from 1936 onwards, he will discover the human evolution as a prolific field of interest; his most important discoveries in this phase are the remains of hominids in the karst caves of South Africa, including Mrs. Ples - Plesianthropus transvaalensis (today Australopithecus africanus).

Fig.3. Dr. Robert Broom, along with "Mrs. Ples" (image from KOHRING & SCHLÃœTER 2004).

Broom has been described as a difficult personality with many "strange" habits.
When searching for fossils, he always went in suit and with tie, but ongoing discovering fossils, he wrapped them in his clothes, and it could happen that he came back home only in his underwear and shoes .
The ladies of the library of the University did follow a strict rule not to accompany him alone, because he had a bad reputation as a "womanizer."
In his life he wrote at least 450 publications, but this productivity had also its drawbacks, he was very hasty in his work, and many species described by Broom are defined very superficially. The figures in his publications are very typical, hastily drawn lines "thrown" on paper very quickly.

Fig.4. Bauria cynops, species described by Broom in 1937, the drawing shows the typical style used by Broom with his sketches, figure from here.

Broom died on 16. Aprile 1951, after a remarkable career - including five honorary degrees, medals, and the myth has it that his last words refer to his great monograph on the hominids (The South African Fossil Ape-Men - the Australopithecinae) "Now that's finished ... and so am I."


References:


KOHRING, R. & SCHLÜTER, T. (2004): Große Paläontologen: Robert Broom (1866-1951). Fossilien - Zeitschrift für Hobbpaläontologen. Heft 1 Jän./Feb.2004: 26-29
ROGERS, A,W, & DU TOIT, A.L. (1909): An Introduction to the Geology of Cape Colony. With a chapter on the fossil reptiles of the Karroo Formation by R. Broom. With Illustrations and coloured Map. Longmans Green, and Co.; London.
SCHWARZ, E.H.L. (1912): South African Geology. Blackie & Son Limited; London.
SMITH, R.M.H. (1995): Changing fluvial environments across the Permian-Triassic boundary in the Karoo Basin, South Africa and possible causes of tetrapod extinctions. Palaeogeography, Palaeoclimatology, Palaeoecology 117: 81-104

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