Paleoecology of the Middle Pliocene Deer Lodge Local Fauna, Western Montana

Konizeski, Richard L.

doi:10.1130/0016-7606(1957)68[131:potmpd]2.0.co;2

Cited by 14 publications

(4 citation statements)

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“…Upper Eocene basin deposits have long been known from Sage Creek, in southwester_nmost Montana (Douglass, 1903, p. 145-146; recently restudied by H~ugh, 1955) and now from the Three Forks quadrangle, but in most places the oldest basin fills seem to be lowest Oligocene, as indicated in the most recently issued Tertiary correlation chart (Wood and others, 1941). The youngest fossiliferous basin deposits in the Three Forks vicinity are of Pliocene age, but in basins farther west the youngest dated deposits of the basin-filling sequence seem generally of late Miocene age, though middle Pliocene basin deposits occur in Deer Lodge Valley (Konizeski, 1957). Both the earliest and latest time of filling may in many places not be datable due to lack of fossils or exposures.…”

Section: Names and Correl_ Ation Of Unitsmentioning

confidence: 89%

Geology of the Three Forks quadrangle, Montana, with sections on petrography of igneous rocks

Robinson¹,

Barnett²

1963

Professional Paper

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The Three Forks quadrangle at the head of the Missouri River, has a long stratigraphic succession. The oldest rocks are Precambrian gneiss, derived from arkosic sandstone, and amphibolite, probably altered from mafic sills and lava flows.The unmetamorphosed sedimentary rocks range in age from late Precambrian to Recent, have an aggregate thickness of about 11,000 feet, and underlie about 85 percent of the quadrangle. The only systems not represented are Ordovician, Silurian, and Triassic. The oldest unmetamorphosed sedimy'1tary rocks are at least 4,000 feet of marine micaceous arkose and conglomerate, the North Boulder formation of the Belt series of late Precambrian age. The formation is a wedge arkose controlled by a buried east-west fault of pre-Belt or Belt age here named the Willow Creek fault. l Tonkinella cf. T. stephenensis Kobayashi Kootenia sp. (with 10 long marginal spines) Bolaspis sp. indet.

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Section: Names and Correl_ Ation Of Unitsmentioning

confidence: 89%

Geology of the Three Forks quadrangle, Montana, with sections on petrography of igneous rocks

Robinson¹,

Barnett²

1963

Professional Paper

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“…Preferential micritization around buried bone began with bacterial decay that produced a reduction halo around the bones some 0´5 m below the¯oodplain surface. Later, microcrystalline calcium carbonate was precipitated from groundwater within the reduction envelope and onto the bone surface (Konizeski 1957). The uncompressed state of the skull attests to the early lithi®cation of the calcareous nodule, before the surrounding mud was fully compacted.…”

Section: Text-®gures 2±6mentioning

confidence: 99%

A new galesaurid (Therapsida: Cynodontia) from the Lower Triassic of South Africa

Sidor

Smith

2004

Palaeontology

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ABSTRACT. A new galesaurid cynodont, Progalesaurus lootsbergensis gen. et sp. nov., is described on the basis of a well-preserved skull, lower jaw, right scapula and left atlantal neural arch. Autapomorphies of Progalesaurus include postcanine teeth bearing numerous mesial and distal accessory cusps that¯ank a recurved main cusp, a post-temporal fenestra bordered by the squamosal ventrally and a large external naris. Progalesaurus is similar to Galesaurus in possessing a poorly de®ned masseteric fossa on the dentary, a strongly recurved main cusp of the postcanine dentition, an incomplete secondary palate and a similar basisphenoid-parasphenoid morphology. A cladistic analysis of ten early cynodont genera resolves a monophyletic Galesauridae encompassing Cynosaurus, Progalesaurus and Galesaurus, although support for this clade is weak. Procynosuchus and Dvinia are placed at the base of Cynodontia whereas Thrinaxodon and Platycraniellus are positioned higher, but outside of Eucynodontia. The holotype and only known specimen of Progalesaurus was collected during systematic prospecting of Permo/Triassic boundary strata at New Lootsberg Pass, Graaff-Reinet District, South Africa. The discovery of Progalesaurus increases the number of valid Early Triassic cynodonts to four and sheds light on the tempo of early cynodont diversi®cation after the end-Permian mass extinction.KEY WORDS: Cynodontia, Galesauridae, South Africa, Permo/Triassic, Balfour Formation, phylogeny, mass extinction.M A M M A L I A N hallmarks such as a bony secondary palate, multicusped postcanine teeth, double occipital condyles and jaw adductor musculature differentiated into temporalis and masseter components ®rst appeared in Late Permian (c. 255 Ma) cynodont therapsids (Hopson 1994; Rubidge and Sidor 2001), the richest fossil record of which hails from the Beaufort Group of South Africa (Kitching 1977;Rubidge 1995).Cynodonts from the Upper Permian and Lower Triassic rocks of South Africa are represented by a handful of genera traditionally divided into two families, Procynosuchidae and Galesauridae (Hopson and Crompton 1969; Kemp 1982). The former includes only Procynosuchus delaharpeae, whereas the latter includes Bolotridon frerensis, Cynosaurus suppostus, Galesaurus planiceps, Platycraniellus elegans and Thrinaxodon liorhinus. Although numerous coeval cynodont taxa were initially recognized (e.g. Haughton and Brink 1954), more recent taxonomic work has demonstrated that the above taxa are the only valid South African forms (Hopson and Kitching 1972). Moreover, phylogenetic studies have shown that Thrinaxodon is more closely related to mammals than it is to Galesaurus, and the family Galesauridae is therefore paraphyletic as traditionally de®ned (Hopson 1991). This paper has two aims. The ®rst is to document the morphology of a new Triassic cynodont collected within 36 m of the Permo/Triassic boundary. The second is to place this taxon within the context of early cynodont diversi®cation by incorporating it into a lower-level cladistic analysis ...

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“…Because of the above relationships the sediments are believed to be younger than the vent. An early Miocene vertebrate fauna (Konizeski, 1957;Wood and Konizeski, 1965) has been collected from these sediments.…”

Section: Tertiary Sedimentary Depositsmentioning

confidence: 99%