Galula Formation
The Galula Formation is a geological formation located south of Lake Rukwa in Tanzania, part of the Red Sandstone Group of the Rukwa Rift Basin. Along with the unconformably overlying Oligocene Nsungwe Formation. It is divided into two members, the lower Mtuka Member and the upper Namba Member.[1]
| Galula Formation Stratigraphic range: Aptian-Campanian ~120–75 Ma | |
|---|---|
| Type | Geological formation |
| Unit of | Red Sandstone Group |
| Sub-units | Mtuka Member, Namba Member |
| Underlies | Unconformity with Nsungwe Formation |
| Overlies | Unconformity with Karoo Supergroup or basement |
| Thickness | 600–3,000 m (2,000–9,800 ft) |
| Lithology | |
| Primary | Sandstone |
| Other | Conglomerate, mudstone |
| Location | |
| Coordinates | 7.1°S 31.2°E |
| Approximate paleocoordinates | 28.8°S 16.5°E |
| Region | Rukwa, Mbeya Region |
| Country |  Tanzania |
| Extent | African Great Lakes, Rukwa Rift Basin |
| Type section | |
| Named for | Galula |
| Named by | Roberts et al. |
| Location | Galula Coalfields |
| Year defined | 2010 |
| Coordinates | 8°40′55.6″S 32°53′33.5″E |
| Thickness at type section | 520 m (1,710 ft) |
  Galula Formation (Tanzania) | |
The age of the deposit is poorly constrained, with the Mtuka Member likely being Aptian to Cenomanian in age, while the Namba Member being Cenomanian to Campanian in age based on Geomagnetic reversals.[2] It is correlated with the Dinosaur Beds of Malawi.
The formation is fossiliferous, with Dinosaurs and Crocodyliformes being known from the formation.
Geology
Lithology
The Lithology of the formation is a sequence of red, pink, purple and occasionally white colored sandstones, conglomerates and mudstones. The Mtuka member is 160–180 m thick in the type section, and is typified by coarser sandstone, a higher frequency of conglomerates, higher proportions of extraformational clasts, thicker and a greater frequency of overbank siltstone and mudstone lenses and a higher proportion of paleosols. While the Namba member is between 340–360 m in the type section, and is less variable in facies, predominated by very fine-to medium-grained sandstones with less overbank mudstone and siltstone lenses.
Vertebrate paleofauna
Fish
| Fish of the Galula Formation | ||||||
|---|---|---|---|---|---|---|
| Genus | Species | Locality | Stratigraphic position | Abundance | Notes | Images |
| Lupaceradotus | L. useviaensis | RRBP 2004-06-30 | Lungfish | |||
| Ceratodontidae | Indeterminate | Mtuka Member | Lungfish | |||
Sauropsids
| Sauropsids of the Galula Formation | ||||||
|---|---|---|---|---|---|---|
| Genus | Species | Locality | Stratigraphic position | Abundance | Notes | Images |
| Pakasuchus[3] | P. kapilimai | RRBP 2007-04 | Namba Member | Articulated skull and skeleton, and referred partial skull |  | |
| Rukwasuchus[4] | R. yajabalijekundu | Namba 2 | Middle Namba member | Partial skull | Peirosaurid | |
| Rukwatitan[5] | R. bisepultus | Locality RRBP 2007-02 (Namba 2) | Middle Namba member | Partial skeleton | Titanosaur |  |
| Shingopana[6] | S. songwensis | TZ-07 | Namba Member | Partial Skeleton | Titanosaur | |
| Mnyamawamtuka | M. moyowamkia | Mtuka Member | Partial skeleton | Titanosaur | ||
| Notosuchia | Indeterminate | Namba Member | ||||
| Testudines | Indeterminate | Mtuka and Namba Members | Plastron and carapace fragments | |||
| Theropoda[7] | Indeterminate | Mtuka and Namba Members | A pair of articulated proximal caudal vertebrae, 11 teeth | |||
Mammals
| Mammals of the Galula Formation | ||||||
|---|---|---|---|---|---|---|
| Genus | Species | Locality | Stratigraphic position | Abundance | Notes | Images |
| Galulatherium[8] | G. jenkinsi | TZ-07 | Namba Member | Left dentary | Probable Gondwanathere[9] |  |
References
- Roberts, Eric M.; O’Connor, Patrick M.; Stevens, Nancy J.; Gottfried, Michael D.; Jinnah, Zubair A.; Ngasala, Sifael; Choh, Adeline M.; Armstrong, Richard A. (May 2010). "Sedimentology and depositional environments of the Red Sandstone Group, Rukwa Rift Basin, southwestern Tanzania: New insight into Cretaceous and Paleogene terrestrial ecosystems and tectonics in sub-equatorial Africa". Journal of African Earth Sciences. 57 (3): 179–212. doi:10.1016/j.jafrearsci.2009.09.002. ISSN 1464-343X.
- Widlansky, Sarah J.; Clyde, William C.; O'Connor, Patrick M.; Roberts, Eric M.; Stevens, Nancy J. (March 2018). "Paleomagnetism of the Cretaceous Galula Formation and implications for vertebrate evolution". Journal of African Earth Sciences. 139: 403–420. doi:10.1016/j.jafrearsci.2017.11.029. ISSN 1464-343X.
- O’Connor, Patrick M.; Sertich, Joseph J. W.; Stevens, Nancy J.; Roberts, Eric M.; Gottfried, Michael D.; Hieronymus, Tobin L.; Jinnah, Zubair A.; Ridgely, Ryan; Ngasala, Sifa E. (August 2010). "The evolution of mammal-like crocodyliforms in the Cretaceous Period of Gondwana". Nature. 466 (7307): 748–751. doi:10.1038/nature09061. ISSN 0028-0836. PMID 20686573.
- Sertich, Joseph J. W.; O’Connor, Patrick M. (2014-04-16). "A new crocodyliform from the middle Cretaceous Galula Formation, southwestern Tanzania". Journal of Vertebrate Paleontology. 34 (3): 576–596. doi:10.1080/02724634.2013.819808. ISSN 0272-4634.
- Gorscak, Eric; O'Connor, Patrick M.; Stevens, Nancy J.; Roberts, Eric M. (2014-07-29). "The basal titanosaurianRukwatitan bisepultus(Dinosauria, Sauropoda) from the middle Cretaceous Galula Formation, Rukwa Rift Basin, southwestern Tanzania". Journal of Vertebrate Paleontology. 34 (5): 1133–1154. doi:10.1080/02724634.2014.845568. ISSN 0272-4634.
- Gorscak, Eric; O'Connor, Patrick M.; Roberts, Eric M.; Stevens, Nancy J. (2017-07-04). "The second titanosaurian (Dinosauria: Sauropoda) from the middle Cretaceous Galula Formation, southwestern Tanzania, with remarks on African titanosaurian diversity". Journal of Vertebrate Paleontology. 37 (4): e1343250. doi:10.1080/02724634.2017.1343250. ISSN 0272-4634.
- O’Connor, Patrick M.; Gottfried, Michael D.; Stevens, Nancy J.; Roberts, Eric M.; Ngasala, Sifa; Kapilima, Saidi; Chami, Remigius (March 2006). "A new vertebrate fauna from the Cretaceous Red Sandstone Group, Rukwa Rift Basin, Southwestern Tanzania". Journal of African Earth Sciences. 44 (3): 277–288. doi:10.1016/j.jafrearsci.2005.11.022. ISSN 1464-343X.
- OConnor, Patrick; Krause, David; Stevens, Nancy; MacPhee, Ross; Groenke, Joseph; Kalthoff, Daniela (2019). "A new mammal from the Upper Cretaceous (Turonian–Campanian) Galula Formation, southwestern Tanzania". Acta Palaeontologica Polonica. 64. doi:10.4202/app.00568.2018.
- KRAUSE, DAVID W.; GOTTFRIED, MICHAEL D.; O’CONNOR, PATRICK M; ROBERTS, ERIC M. (2003). "A Cretaceous mammal from Tanzania" (PDF). Acta Palaeontologica Polonica. 48 (3): 321–330.