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 ~ | |
| 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°06′S 31°12′E / 7.1°S 31.2°E |
| Approximate paleocoordinates | 28°48′S 16°30′E / 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 / 8.682111°S 32.892639°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
editLithology
editThe 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.[1]
Vertebrate paleofauna
editFish
edit| 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 | |||
Crocodyliformes
edit| Crocodyliformes of the Galula Formation | ||||||
|---|---|---|---|---|---|---|
| Genus | Species | Locality | Stratigraphic position | Abundance | Notes | Images |
| Pakasuchus[3] | P. kapilimai | RRBP 2007-04[3] | Namba Member[3] | [Two] skulls and an articulated skeleton.[3] | A notosuchian crocodyliform with mammal-like teeth.[3] | 
|
| Rukwasuchus[4] | R. yajabalijekundu | Namba 2[4] | Middle Namba member[4] | A partial skull and isolated teeth.[4] | A notosuchian crocodyliform, and the only known sub-Saharan peirosaurid from Africa.[4] | |
| Notosuchia[5] | Indeterminate | Namba Member[5] | ||||
Dinosaurs
edit| Dinosaurs of the Galula Formation | ||||||
|---|---|---|---|---|---|---|
| Genus | Species | Locality | Stratigraphic position | Abundance | Notes | Images |
| Mnyamawamtuka[6] | M. moyowamkia | Mtuka Member[6] | An anterior cervical vertebral neural arch, cervical vertebral centra, partial dorsal vertebrae, sacral neural arch, partial sacral centra, sacral ribs, caudal vertebral neural arches, centra, chevrons, numerous dorsal rib fragments, scapula, sternal plate, humeri, partial ulna, metacarpal I, metacarpal III, partial ischium, partial pubis, partial femora, tibiae, fibula, metatarsal I, metatarsal II, metatarsal III, metatarsal IV, metatarsal V, pedal phalanges, ungual, and numerous unidentifiable fragments.[6] | A basal lithostrotian titanosaur with heart-shaped caudal vertebrae.[6] | ||
| Rukwatitan[7] | R. bisepultus | Locality RRBP 2007-02 (Namba 2)[6] | Middle Namba member[6] | Posterior cervical vertebrae, partial anterior dorsal vertebral neural arch, anterior caudal vertebrae, middle caudal vertebrae, chevrons, multiple partial dorsal ribs, distal scapula, partial coracoids, humerus, partial ulna, ilium, and proximal pubis.[6] | A basal lithostrotian titanosaur.[6] | |
| Shingopana[5] | S. songwensis | TZ-07[6] | Namba Member[5] | An angular, partial anterior cervical vertebra, partial middle-to-posterior cervical vertebrae, partial cervical ribs, partial dorsal ribs, humerus, pubis, and many incomplete and/or unidentifiable fragments pertaining to the axial skeleton.[6] | A lithostrotian titanosaur.[6] | |
| Theropoda[8] | Indeterminate | Mtuka and Namba Members[8] | A pair of articulated proximal caudal vertebrae, and 11 teeth.[5] | An indeterminate theropod.[5] | ||
Turtles
edit| Turtles of the Galula Formation | ||||||
|---|---|---|---|---|---|---|
| Genus | Species | Locality | Stratigraphic position | Abundance | Notes | Images |
| Testudines[5] | Indeterminate | Mtuka and Namba Members.[5] | Plastron and carapace fragments.[5] | |||
Mammals
edit| Mammals of the Galula Formation | ||||||
|---|---|---|---|---|---|---|
| Genus | Species | Locality | Stratigraphic position | Abundance | Notes | Images |
| Galulatherium[9] | G. jenkinsi | TZ-07 | Namba Member | Left dentary | Probable Gondwanathere[10] |  |
References
edit- ^ a b 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. Bibcode:2010JAfES..57..179R. 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. Bibcode:2018JAfES.139..403W. doi:10.1016/j.jafrearsci.2017.11.029. ISSN 1464-343X.
- ^ a b c d e 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. Bibcode:2010Natur.466..748O. doi:10.1038/nature09061. ISSN 0028-0836. PMID 20686573. S2CID 4405106.
- ^ a b c d e 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. Bibcode:2014JVPal..34..576S. doi:10.1080/02724634.2013.819808. ISSN 0272-4634. S2CID 16644660.
- ^ a b c d e f g h i 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. Bibcode:2017JVPal..37E3250G. doi:10.1080/02724634.2017.1343250. ISSN 0272-4634. S2CID 90885040.
- ^ a b c d e f g h i j k Gorscak, Eric; O’Connor, Patrick M. (2019). "A new African titanosaurian sauropod dinosaur from the middle Cretaceous Galula Formation (Mtuka Member), Rukwa Rift Basin, southwestern Tanzania". PLoS ONE. 2 (14): e0211412. Bibcode:2019PLoSO..1411412G. doi:10.1371/journal.pone.0211412. PMC 6374010. PMID 30759122.
- ^ 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. Bibcode:2014JVPal..34.1133G. doi:10.1080/02724634.2014.845568. ISSN 0272-4634. S2CID 677002.
- ^ a b 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. Bibcode:2006JAfES..44..277O. 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.