Mahenge Formation

Mahenge Formation
Stratigraphic range:
TypeSedimentary
OverliesPrecambrian basement (Nyanzian Belt)
Lithology
PrimaryMudstone, shale
Location
Coordinates4°48′S 34°18′E / 4.8°S 34.3°E / -4.8; 34.3
Approximate paleocoordinates18°00′S 33°00′E / 18.0°S 33.0°E / -18.0; 33.0
CountryTanzania
Type section
Named forMahenge
Mahenge Formation (Tanzania)

The Mahenge Formation[1] is a Middle Eocene-aged geological formation and Konservat-Lagerstätte from Tanzania.[2] It contains a high variety of exceptionally-preserved fossils, including many of the earliest fossil records of dominant freshwater fish groups found in Africa today. It represents one of the most comprehensive Paleogene-aged African fossil deposits south of the Sahara. Based on fossil plant remains found in the formation, the Mahenge lake was situated within legume-dominated woodlands reminiscent of modern miombo forests.[3]

It was deposited within a former maar lake formed from a volcanic intrusion into the Precambrian bedrock via a kimberlite pipe.[4] It has been dated to the Lutetian, roughly 46.0 million years ago.[2] Unusually, relatively few fossil insect remains are known from the lake, unlike with other maar deposits. It is thought that the high diversity of fish in the lake may have led to most insects being consumed before they could be fossilized.[5]

Paleobiota

Bony fish

Genus Species Material Notes Images
Chaulopareion C. mahengeense An osteoglossid.[6]
Chrysichthys C. mahengeensis A claroteid catfish.[7]
Eocitharinus E. macrognathus A citharinid.[8]
Mahengecharax M. carrolli A potential alestid characiform, taxonomic identity disputed.[9][10]
Mahengechromis M. brachycranium A cichlid, forming a species flock.[11][12]
M. curvifrons
M. ellipticus
M. plethos
M. rotundus
Mahengichthys M. singidaensis A shellear.[13]
Palaeodenticeps P. tanganikae A relative of the denticle herring.
Singida S. jacksonoides A singidid osteoglossiform.[14]

Amphibians

Genus Species Material Notes Images
Singidella S. laticostata A pipid frog.[15]

Mammals

Genus Species Material Notes Images
Tanzanycteris T. mannardi A tanzanycterid bat.[16]

Insects

Genus Species Material Notes Images
Mahengea M. mckayi A scarab beetle.[5]

Plants

Genus Species Material Notes Images
Acacia A. mahengensis An acacia.[17]
Aphanocalyx A. singidaensis A legume.[17]
cf. Cynometra C. sp. A legume.[17]

References

  1. ^ McMahan, Caleb D.; Chakrabarty, Prosanta; Sparks, John S.; Smith, W. M. Leo; Davis, Matthew P. (2013). "Temporal patterns of diversification across global cichlid biodiversity (Acanthomorpha: Cichlidae)". PLOS ONE. 8 (8): e71162. Bibcode:2013PLoSO...871162M. doi:10.1371/journal.pone.0071162. ISSN 1932-6203. PMC 3747193. PMID 23990936.
  2. ^ a b Uhl, Dieter; Wuttke, Michael; Smith, Krister T.; Wedmann, Sonja; Lehmann, Thomas (2024-12-01). "Pre-Quaternary maar lakes/volcanogenic lakes as Konservat Lagerstätten—Messel and beyond". Palaeobiodiversity and Palaeoenvironments. 104 (4): 753–761. Bibcode:2024PdPe..104..753U. doi:10.1007/s12549-024-00636-z. ISSN 1867-1608.
  3. ^ Kaiser, Thomas M.; Ansorge, Jörg; Arratia, Gloria; Bullwinkel, Volker; Gunnell, Gregg F.; Herendeen, Patrick S.; Jacobs, Bonnie; Mingram, Jens; Msuya, Charles; Musolff, Andreas; Naumann, Rudolf; Schulz, Ellen; Wilde, Volker (2006-09-01). "The maar lake of Mahenge (Tanzania) unique evidence of Eocene terrestrial environments in sub-Sahara Africa". Zeitschrift der Deutschen Gesellschaft für Geowissenschaften. 157 (3): 411–431. Bibcode:2006ZDGG..157..411K. doi:10.1127/1860-1804/2006/0157-0411. ISSN 1860-1804.
  4. ^ Harrison, Terry; Msuya, Charles P.; Murray, Alison M.; Jacobs, Bonnie Fine; Báez, Ana Maria; Mundil, Roland; Ludwig, Kenneth R. (2001), Gunnell, Gregg F. (ed.), "Paleontological Investigations at the Eocene Locality of Mahenge in North-Central Tanzania, East Africa", Eocene Biodiversity: Unusual Occurrences and Rarely Sampled Habitats, Boston, MA: Springer US, pp. 39–74, doi:10.1007/978-1-4615-1271-4_2, ISBN 978-1-4615-1271-4, retrieved 2025-05-02
  5. ^ a b Strümpher, Werner P.; Scholtz, Clarke H.; Schlüter, Thomas (2023-03-29). "An Eocene fossil scarab beetle (Coleoptera: Scarabaeoidea) from Tanzania". South African Journal of Science. 119 (3/4). doi:10.17159/sajs.2023/14681. hdl:2263/90265. ISSN 1996-7489.
  6. ^ MURRAY, ALISON M.; WILSON, MARK V. H. (2005-06-01). "Description of a new Eocene osteoglossid fish and additional information on †Singida jacksonoides Greenwood and Patterson, 1967 (Osteoglossomorpha), with an assessment of their phylogenetic relationships". Zoological Journal of the Linnean Society. 144 (2): 213–228. doi:10.1111/j.1096-3642.2005.00170.x. ISSN 0024-4082.
  7. ^ Murray, Alison M; Budney, Lisa A (2003). "A new species of catfish (Claroteidae, Chrysichthys) from an Eocene crater lake in East Africa". Canadian Journal of Earth Sciences. 40 (7): 983–993. Bibcode:2003CaJES..40..983M. doi:10.1139/e03-031. ISSN 0008-4077.
  8. ^ Murray, Alison M. (2003). "A new Eocene citharinoid fish (Ostariophysi: Characiformes) from Tanzania". Journal of Vertebrate Paleontology. 23 (3): 501–507. Bibcode:2003JVPal..23..501M. doi:10.1671/1854. ISSN 0272-4634.
  9. ^ Murray, Alison M (2003). "A new characiform fish (Teleostei: Ostariophysi) from the Eocene of Tanzania". Canadian Journal of Earth Sciences. 40 (4): 473–481. Bibcode:2003CaJES..40..473M. doi:10.1139/e02-108. ISSN 0008-4077.
  10. ^ ZANATA, ANGELA M.; VARI, RICHARD P. (2005-09-01). "The family Alestidae (Ostariophysi, Characiformes): a phylogenetic analysis of a trans-Atlantic clade". Zoological Journal of the Linnean Society. 145 (1): 1–144. doi:10.1111/j.1096-3642.2005.00183.x. ISSN 0024-4082.
  11. ^ Murray, Alison M. (2001-04-07). "The oldest fossil cichlids (Teleostei: Perciformes): indication of a 45 million-year-old species flock". Proceedings of the Royal Society of London. Series B: Biological Sciences. 268 (1468): 679–684. doi:10.1098/rspb.2000.1570. PMC 1088656. PMID 11321055.
  12. ^ Murray, Alison M. "The Eocene cichlids (Perciformes:Labroidei) of Mahenge, Tanzania /". escholarship.mcgill.ca. Robert L. (Supervisor) Carroll. Retrieved 2025-04-22.
  13. ^ Davis, M.P.; Arratia, G.; Kaiser, T.M. (2013). "The first fossil shellear (Gonorynchiformes: Kneriidae) from the Eocene lake of Mahenge (Tanzania)". Mesozoic Fishes 5 - Global Diversity and Evolution. F. Pfeil. pp. 325–362. ISBN 978-3-89937-159-8.
  14. ^ MURRAY, ALISON M.; WILSON, MARK V. H. (2005-06-01). "Description of a new Eocene osteoglossid fish and additional information on †Singida jacksonoides Greenwood and Patterson, 1967 (Osteoglossomorpha), with an assessment of their phylogenetic relationships". Zoological Journal of the Linnean Society. 144 (2): 213–228. doi:10.1111/j.1096-3642.2005.00170.x. ISSN 0024-4082.
  15. ^ Báez, Ana Maria; Harrison, Terry (2005). "A New Pipine Frog from an Eocene Crater Lake in North-Central Tanzania". Palaeontology. 48 (4): 723–737. Bibcode:2005Palgy..48..723B. doi:10.1111/j.1475-4983.2005.00477.x. ISSN 1475-4983.
  16. ^ "OLDEST PLACENTAL MAMMAL FROM SUB-SAHARAN AFRICA: EOCENE MICROBAT FROM TANZANIA - EVIDENCE FOR EARLY EVOLUTION OF SOPHISTICATED ECHOLOCATION by Gregg F. Gunnell, Bonnie Fine Jacobs, Patrick S. Herendeen, Jason J. Head, Elizabeth Kowalski, Charles P. Msuya, Ferdinand A. Mizambwa, Terry Harrison, Jörg Habersetzer, and Gerhard Storch". palaeo-electronica.org. Retrieved 2025-04-22.
  17. ^ a b c Herendeen, P. S.; Jacobs, B. F. (2000). "Fossil legumes from the Middle Eocene (46.0 Ma) Mahenge Flora of Singida, Tanzania". American Journal of Botany. 87 (9): 1358–1366. Bibcode:2000AmJB...87.1358H. doi:10.2307/2656727. ISSN 0002-9122. JSTOR 2656727. PMID 10991905.