Tina Negus
Tina Negus | |
|---|---|
| Born | Christina L. Batty 1941 Grantham, England |
| Citizenship | British |
| Alma mater | University of Reading |
| Known for | Discovery of Charnia Mollusks of River Thames |
| Scientific career | |
| Fields | Zoology Ecology |
| Institutions | Durham University |
Tina Negus (Christina L. née Batty, born 1941[1]) is a British zoologist, painter and poet[2] who is credited as the original discoverer of Charnia, the first ever known Precambrian fossil.[3][4] A fossil enthusiast since childhood, she found the first specimen of frond-like fossil at Charnwood Forest in Leicestershire during a summer vacation in 1956.[5] She studied zoology, botany and geography at the University of Reading.[6] She took up zoology for her postgraduate degree and her dissertation research on mussel diversity and abundance, published in the Journal of Animal Ecology in 1966,[7] became a fundamental information on the degree of pollution in the River Thames.[8][9] In recognition of her pioneering work, the University of Reading commissioned the Tina Negus Prize to graduate students of biology since 2019.[6]
Biography
[edit]Negus was born in Grantham, Lincolnshire, England.[10] Growing up in "Liassic (limestone sediments of Early Jurassic, about 200 to 180 million years old) sandstones and clays", as she described her upbringing, her childhood activities were mostly collecting fossils, and was familiar with ammonites and belemnites.[5] During her school vacations, she explored interesting geological sites such as Peak District and Kent. During her secondary schooling, she read a small handbook Geology of the Ancient Rocks of Charnwood Forest, Leicestershire (1947)[11] by William Whitehead Watts,[12] who had documented the Precambrian (roughly older than 530 million years ago) nature of the Charnwood rocks.[13] This information inspired her for a field visit to Charnwood.[5]
Enthused by her passion for fossils, she decided to become a geologist and study geology in higher education, which was dissuaded by her geography teacher in the sixth form. She therefore studied an undergraduate course in zoology, botany and geography at the University of Reading in 1961. She then continued with a postgraduate course in zoology at the same university. After her master's degree, she briefly joined Durham University.[7] After her marriage, she gave up career in academics and developed her talents in painting, photography and poetry.[2]
Discovery of the Precambrian fossil
[edit]First discovery
[edit]For the 1956 summer vacation, Negus persuaded her family to explore Charnwood Forest with of pretext of collecting blueberries. According to her memory, it would have been around June and July as the blueberries were not yet ripe. That was not her priority, but instead was searching for fossils among the deepest rocks exposed. Furnished with maps from Watts's book, she already knew the best locations to look for. At an abandoned quarry of turbidites (a type of sedimentary rocks deposited from turbidity currents of oceans), she found large slabs of rocks inclined to form a wall. The rock faces were too smooth and vertical that she could only scraped along the lower bases. Hidden behind some roots and thickets, she saw a clear impression on one rock that looked like a fern.[10] She also knew that it was not a proper fern as the frond had no stem or branching veins.[1] It was obvious to her that it was a fossil in a Precambrian rock. Her parents did not have connections with scientists so they only encouraged her to tell her teachers.[10]
For Negus, the closest to a scientist in palaeontology was her geography teacher. As she described the discovery, her teacher straightforwardly explained that there could be no fossils in Precambrian rocks, that what she found was either not a fossil or the rocks were much younger. She could not convince anyone, but her confidence remained unfeigned. During winter vacation of that year in December, she again asked her parents to make another trip to Charnwood Forest. Then equipped with her father's mining hammer, they tried to extract the fossils from the rock slab, but only to find that the hand-tool could not make a crack on the hard rock.[14] Instead, Negus took a pencil and made a stencil trace of the fossil on two sheets of paper. Trying to identify the fossil herself, she searched through all possible information from books and local museum, but found no matching image of her ancient frond. She kept her pencil rubbing in a folder for any future clue.[1]
Rediscovery and identification
[edit]In May 1957, Roger Mason, Richard Blatchford and Richard Allen from Wyggeston Grammar School for Boys in Leicester went rock-climbing in the Charnwood Forest. It was Blachford who first spotted the fossil imprint and thought it was a feather. A 15-year-old Mason climbed down to the spot and found that it more fern-like. He already knew that the rocks were of Precambrian and nobody expected fossil of that kind. He took a rubbing of it and showed it to his father at home. Mason's father was a teacher at the University of Leicester and quickly approached his young colleague and geologist, Trevor D. Ford. Sceptical of a fossil in Precambrian rocks, Ford and the Masons went to Charnwood Forest and confirmed the fossil.[15]
In September 1957, Ford with professional miners excavated the rock and extracted the fossil to be maintained at the Leicester Museum & Art Gallery (New Walk Museum and Art Gallery, prior to 2022).[14] Ford made further exploration of Charnwood Forest for any other specimens and found five more fern-like specimens and twelve ring-like fossils. Upon analysis, he identified the two types of fossils as algae, and for the fern-like type he created a scientific name Charnia masoni, to credit the place and discoverer.[16][17] He reported the description in the September 1958 issue of the Proceedings of the Yorkshire Geological Society, drawing a conclusion:
Several specimens of two new fossils recently found in the Woodhouse Beds of the Charnwood Forest Pre-Cambrian succession are described and named Charnia masoni and Charniodiscus concentricus... The evidence points to their being algae.[18]
Charnia masoni became the most iconic[19] and first ever known Precambrian organism.[20][21][a]
Ecology of River Thames
[edit]In her master's degree course in zoology at the University of Reading, Negus researched on the ecology of the River Thames for her dissertation in 1964 and focussed on the diversity and abundance of mussels.[22] She published her findings in the Journal of Animal Ecology in 1966,[7] which remained unnoticed for over half a century. She reported that the major species of mussels were the duck mussel (Anodonta anatina) and the painter's mussel (Unio pictorum); A. minima and U. tumidus were also common, and the rarest were A. cygnea. Negus's selection of the mussels was notable in that the animals account for 90% of all living organisms recorded by weight on the Thames' riverbed.[8] The importance of her research was realised and revived in 2022 when University of Cambridge scholar Isobel Ollard re-investigated the same mussel ecology at the same site.[8] Since the late 1960's, it has been established that the different biological features of mussels are reliable scientific indicators of the health of the water bodies.[23][24]
In 2023, Ollard reported her investigation in the same Journal of Animal Ecology.[9] Her findings revealed that the general mussel communities had declined since Negus's report by almost 95%.[8][25] The duck mussels had decreased to 1.1% , and the painter’s mussel, to 3.2%; while the rare species had completely disappeared.[26] The alarming case was not only on the number, but also on the reduced sizes of the mussels, which is a scientific method of determining the deterioration of the Thames' ecosystem. The size and growth rates had reduced by 10 to 30%.[8] Ollard's supervisor and co-author David Aldridge explained the significance of the study: "While this might seem like a rather parochial little study of a single site in a single river in the UK, it actually provides an important warning signal about the world's freshwaters."[25] Thames in the late 1950s and early 1960s was in its highest level of pollution; in 1957, scientists at the Natural History Museum of London considered the Thames so polluted that they declared it "biologically dead," since it would not be able to sustain any major life form.[27][28] According to Ollard, the policies on Thames conservation had prevented the total disappearance of the mussels and the stable, albeit critically low number, is an indication that the river ecosystem is improving.[8]
In recognition of her pioneering work, the University of Reading commissioned the Tina Negus Prize to graduate students of biology since 2019.[6]
Footnote
[edit]- ^ Other fossils later identified as belonging to Precambrian were discovered earlier, such as Aspidella from Newfoundland in 1868 and Dickinsonia from Ediacaran Hills, Australia, in 1947, but their nature as organism fossil and their geological age were not established until the 1960s.
References
[edit]- ^ a b c Stadler, Marta Macho (2019-01-31). "Tina Negus (1941): "¡Alguien ha cogido mi fósil!"" [Someone took my fossil!]. Mujeres con ciencia (in Spanish). Retrieved 2024-09-20.
- ^ a b Becky (2015-03-04). "Tina Negus". Trowelblazers. Retrieved 2024-09-20.
- ^ Segessenman, Daniel C.; Peters, Shanan E. (2023-01-23), Whitmeyer, Steven J.; Williams, Michael L.; Kellett, Dawn A.; Tikoff, Basil (eds.), "Macrostratigraphy of the Ediacaran System in North America", Laurentia: Turning Points in the Evolution of a Continent, Geological Society of America, pp. 399–424, doi:10.1130/2022.1220(21), ISBN 978-0-8137-1220-8, retrieved 2024-09-20
- ^ Riding, James B.; Worley, Noel E. (2020-05-30). "Trevor David Ford (1925–2017)". Proceedings of the Yorkshire Geological Society. 63 (1): 61–62. Bibcode:2020PYGS...63...61R. doi:10.1144/pygs2020-001. ISSN 0044-0604.
- ^ a b c Negus, Tina (2007). "An account of the discovery of Charnia" (PDF). Charnia. Archived from the original on 23 July 2011. Retrieved 20 September 2024.
- ^ a b c Smalley, Julia (2023-03-23). "Trailblazing Research". Connected. University of Reading Alumni and Supporter Engagement. Retrieved 2024-09-20.
- ^ a b c Negus, Christina L. (1966). "A Quantitative Study of Growth and Production of Unionid Mussels in the River Thames at Reading". Journal of Animal Ecology. 35 (3): 513–532. Bibcode:1966JAnEc..35..513N. doi:10.2307/2489. ISSN 0021-8790. JSTOR 2489.
- ^ a b c d e f Ollard, Isobel (2022-11-28). "Mussels are disappearing from the Thames and growing smaller – and it's partly because the river is cleaner". The Conversation. Retrieved 2024-09-20.
- ^ a b Ollard, Isobel; Aldridge, David C. (2023). "Declines in freshwater mussel density, size and productivity in the River Thames over the past half century". Journal of Animal Ecology. 92 (1): 112–123. Bibcode:2023JAnEc..92..112O. doi:10.1111/1365-2656.13835. ISSN 0021-8790. PMC 10100129. PMID 36437493.
- ^ a b c Montoro, Juan Carlos Gil (2024-08-15). "La vida es compleja: Charnia masoni pudo haber sido Charnia battyae" [Life is complex: Charnia masoni may have been Charnia battyae]. Naukas (in Spanish). Retrieved 2024-09-20.
- ^ Watts, William Whitehead (1947). Geology of the Ancient Rocks of Charnwood Forest, Leicestershire: With which is Included the Area about Mountsorrel; Parts of the One-inch Maps (new Series) 141, 155 and 156. Leicester Literary and Philosophical Society. pp. 1–160.
- ^ Bennett, F.W.; Lowe, E.E.; Gregory, H.H.; Jones, F. (1928). "The geology of Charnwood Forest". Proceedings of the Geologists' Association. 39 (3): 241–IN6. Bibcode:1928PrGA...39..241B. doi:10.1016/S0016-7878(28)80014-9.
- ^ Carney, John N. (1999). "Revisiting the Charnian Supergroup: new advances in understanding old rocks". Geology Today. 15 (6): 221–229. Bibcode:1999GeolT..15..221C. doi:10.1046/j.1365-2451.1999.00006.x. ISSN 0266-6979.
- ^ a b Montoro, Juan Carlos Gil (2024-08-15). "La vida es compleja: Charnia masoni pudo haber sido Charnia battyae" [Life is complex: Charnia masoni may have been Charnia battyae]. Naukas (in Spanish). Retrieved 2024-09-20.
- ^ Mason, Roger (2007). "The discovery of Charnia masoni" (PDF). University of Leicester. Archived from the original (PDF) on 8 March 2021. Retrieved 5 April 2016.
- ^ Bowers, A. (2013). "Precambrian fossil discoveries and new fossil localities in Charnwood Forest, Leicestershire". Mercian Geologist. 18: 91−98. S2CID 131624603.
- ^ Ford, Trevor D. (1980-01-01). "The Ediacaran fossils of Charnwood Forest, Leicestershire". Proceedings of the Geologists' Association. 91 (1): 81–83. Bibcode:1980PrGA...91...81F. doi:10.1016/S0016-7878(80)80014-9. ISSN 0016-7878.
- ^ Ford, T.D. (1958). "Precambrian fossils from Charnwood Forest". Yorkshire Geological Society Proceedings. 31 (3): 211–217. Bibcode:1958PYGS...31..211F. doi:10.1144/pygs.31.3.211.
- ^ Dunn, Frances S.; Wilby, Philip R.; Kenchington, Charlotte G.; Grazhdankin, Dmitriy V.; Donoghue, Philip C. J.; Liu, Alexander G. (2019). "Anatomy of the Ediacaran rangeomorph Charnia masoni". Papers in Palaeontology. 5 (1): 157–176. Bibcode:2019PPal....5..157D. doi:10.1002/spp2.1234. ISSN 2056-2802. PMC 6472560. PMID 31007942.
- ^ Antcliffe, Jonathan B.; Brasier, Martin D. (2008). "Charnia at 50: Developmental models for Ediacaran fronds". Palaeontology. 51 (1): 11–26. Bibcode:2008Palgy..51...11A. doi:10.1111/j.1475-4983.2007.00738.x. ISSN 0031-0239.
- ^ Bowers, A. (2014). "Further Precambrian (Ediacaran) fossil discoveries in Charnwood Forest, Leicestershire" (PDF). Mercian Geologist. 18: 175−179. S2CID 55579161.
- ^ "Mussel survey in River Thames - University of Reading". www.reading.ac.uk. 2022-11-02. Retrieved 2024-11-13.
- ^ Seed, R. (1968). "Factors Influencing Shell Shape in the Mussel Mytilus Edulis". Journal of the Marine Biological Association of the United Kingdom. 48 (3): 561–584. Bibcode:1968JMBUK..48..561S. doi:10.1017/S0025315400019159. ISSN 1469-7769.
- ^ Lopes-Lima, Manuel; Sousa, Ronaldo; Geist, Juergen; Aldridge, David C.; Araujo, Rafael; Bergengren, Jakob; Bespalaya, Yulia; Bódis, Erika; et al. (2017). "Conservation status of freshwater mussels in Europe: state of the art and future challenges: Conservation of European freshwater mussels". Biological Reviews. 92 (1): 572–607. doi:10.1111/brv.12244. PMID 26727244.
- ^ a b Ashworth, James (2022-11-28). "Mussels in the Thames have declined by 95% since the 1960s". www.nhm.ac.uk. Retrieved 2024-11-13.
- ^ "Mussel survey reveals alarming degradation of River Thames ecosystem since the 1960s | University of Cambridge". www.cam.ac.uk. 2022-11-28. Retrieved 2024-11-13.
- ^ "The State Of The Thames 2021". www.zsl.org. 2021-11-21. Retrieved 2024-11-13.
- ^ Aridi, Rasha (2021-12-21). "Once Deemed 'Biologically Dead,' a New Report Shows London's River Thames Recovering". Smithsonian Magazine. Retrieved 2024-11-13.