Robert Etheridge jnr, British palaeontologist, was the only child of the British palaeontologist Robert Etheridge (1819-1903). Robert jnr was educated at the Royal School of Mines in London (though he did not take his associateship) and trained as a palaeontologist by his father. He spent most of his adult life in Australia, first as assistant geologist to the Geological Survey of Victoria from March 1866. When the Geological Survey was discontinued in 1869 he went gold mining and in 1871 returned to England to work as underground manager in a coal mine in Wales. In 1873 he became palaeontologist to the Geological Survey of Scotland but the next year accepted an appointment as assistant in the geological department of the British Museum (Natural History) under his father. He was a prolific researcher, publishing more than 100 notes and papers during the period 1873 to 1886, including many on the geology and fossils of eastern Australia. His Catalogue of Australian fossils... stratigraphically and zoologically arranged was published in 1878, followed by a catalogue of publications on the geology and palaeontology of Australia in 1881.
In April 1887 Etheridge was appointed palaeontologist to the Geological Survey of New South Wales and to the Australian Museum in Sydney. He undertook a collecting expedition to Lord Howe Island in 1887 and founded the Records of the Geological Survey in 1889. Most of his research dealt with the palaeontology of Australia. In 1892 he and Jack published a monumental work, Geology and palaeontology of Queensland and New Guinea. Other publications included a monograph on "The Cretaceous molluscs of South Australia" (1902) in the Memoirs of the Royal Society of South Australia, and items on the fossil insects of New South Wales (1890), the palaeozoic and mesozoic fossils of Queensland (1917), and many more, mainly on invertebrate fossils of all types and ages. His work contributed substantially to knowledge of Australian stratigraphy. During the 1890s he served on the councils of both the Royal Society and the Linnean Society of New South Wales. He became curator (director) of the Australian Museum in January 1895.
In 1886 Etheridge and T. Davies described the mineral exhibits of the African colonies (including the Cape of Good Hope and Natal) at the Colonial and Indian Exhibition, in the Mining Journal (Vol. 56, pp. 830-831, 859-860, 889, 919). Etheridge's main contribution to South African science consisted of his description of several collections of fossils assembled by W. Anderson* during the geological survey of Natal and Zululand. His "Report on the fossil plants from St Lucia Bay coalfields" was published in Anderson's First report on the geological survey of Natal and Zululand (pp. 67-76) in 1902. Two subsequent contributions on "Cretaceous fossils of Natal", Parts 1 and 2, appeared in Anderson's second (1904, pp. 69-94) and third (1907, pp. 67-92) Reports. They dealt with the fossils of the Umkwelane Hill deposit and the Umsinene Beds (both in Zululand) respectively.
Etheridge's interests also encompassed other scientific disciplines. He wrote a work on the zoology, geology, and physical geography of Lord Howe Island (1889), and a memoir on stone implements of New South Wales (1916). He also published widely on Australian ethnology and in 1906 established an ethnology department in the Australian Museum. His series of papers on boomerangs was published in the Proceedings of the Linnean Society of New South Wales during 1892-1898. In 1915 he wrote an obituary of William Anderson*, former geologist of the Geological Survey of Natal, for the Geological Magazine. A shy, aloof and austere person, he produced more than 350 publications during his lifetime. He died of pneumonia early in 1920.