The Tiffanian North American Stage on the geologic timescale is the North American faunal stage according to the North American Land Mammal Ages chronology (NALMA), typically set from 60,200,000 to 56,800,000 years BP lasting 3.4 million years .
12-875: It is usually considered to overlap the Selandian and Thanetian within the Paleocene . The Tiffanian is preceded by the Torrejonian and followed by the Clarkforkian NALMA stages. The Tiffanian is considered to contain the following substages: Multituberculata - non-therian mammals Metatheria - marsupials Apatotheria - primitive, arboreal mammals Condylarthra - archaic ungulates Dinocerata - large, tusked herbivores Eulipotyphla - insectivorous mammals Primatomorpha - primates and relatives Proteutheria - basal eutherians Selandian The Selandian
24-590: A southward direction. Since the closure of the North Atlantic–Labrador Sea rift, Greenland has moved roughly in conjunction with North America; thus, there are questions as to whether the Greenland plate should still be considered a separate plate at all. The area between Greenland and Baffin Island is, however, seismically very active, being the location of the epicenter of many earthquakes including
36-752: Is a stage in the Paleocene . It spans the time between 61.6 and 59.2 Ma . It is preceded by the Danian and followed by the Thanetian . Sometimes the Paleocene is subdivided in subepochs, in which the Selandian forms the "middle Paleocene". The Selandian was introduced in scientific literature by Danish geologist Alfred Rosenkrantz in 1924. It is named after the Danish island of Zealand ( Danish : Sjælland ) given its prevalence there. The base of
48-600: Is a shift to siliciclastic deposition due to the uplift and erosion of the Scotland - Shetland area after nearly 40 million years of calcium carbonate deposition. This change occurs at the same time as the onset of a foreland basin formation in Spitsbergen due to compression between Greenland and Svalbard , suggesting a common tectonic cause that altered the relative motions of the Greenland Plate and
60-757: Is at the core of the North American continent . Greenland was formed in two rifting stages from the main body of North America. The first, during the Cretaceous period, formed Baffin Bay . Baffin Bay is the northwestern extension and terminus of the North Atlantic-Labrador Sea rift system that started forming 140 million years ago in the Early Cretaceous epoch . The Labrador Sea started opening 69 million years ago during
72-554: The Eurasian Plate . This plate reorganisation event is also manifest as a change in seafloor spreading direction in the Labrador Sea around this time. The fauna of the Selandian consisted of giant snakes ( Titanoboa ), crocodiles, champsosaurs , Gastornithiformes , owls ; and a few archaic forms of mammals, such as mesonychids , pantodonts , primate relatives plesiadapids , and multiberculates . The flora
84-597: The Maastrichtian age but seafloor spreading appears to have ceased by the Oligocene epoch, 30–35 million years ago. Correlations between tectonic units in Canada and Greenland have been proposed; however, the pre-spreading fit of Greenland to Canada is still not accurately known. A sinistral transtensive rifting which was proposed with NNE-SSW trending mobile transfer zones fits Greenland to Canada directly in
96-616: The Mid-Atlantic Ridge ; and the northeast by the Gakkel Ridge , with its northwest border still being explored. The Greenland craton is made up of some of the oldest rocks on Earth. The Isua greenstone belt in southwestern Greenland contains the oldest known rocks on Earth dated at 3.7–3.8 billion years old. The Precambrian basement of Greenland formed an integral part of the Laurentian Shield that
108-477: The Selandian is close to the boundary between biozones NP4 and NP5. It is slightly after the first appearances of many new species of the calcareous nanoplankton genus Fasciculithus ( F. ulii , F. billii , F. janii , F. involutus , F. tympaniformis and F. pileatus ) and close to the first appearance of calcareous nanoplankton species Neochiastozygus perfectus . At the original type location in Denmark
120-636: The base of the Selandian is an unconformity . The official Global Boundary Stratotype Section and Point (GSSP) was established in the Zumaia section ( 43°18′N 002°16′W / 43.300°N 2.267°W / 43.300; -2.267 ) at the beach of Itzurun in the Basque Country , northern Spain . The top of the Selandian (the base of the Thanetian) is laid at the base of magnetic chronozone C26n. The Selandian Stage overlaps with
132-845: The lower part of the Tiffanian North American Land Mammal Age , the Peligran , Tiupampan and lower Itaboraian South American Land Mammal Ages and part of the Nongshanian Asian Land Mammal Age . It is coeval with the lower part of the Wangerripian Stage from the Australian regional timescale. The start of the Selandian represents a sharp depositional change in the North Sea Basin, where there
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#1732786586677144-451: Was composed of cacti , ferns , and palm trees . 43°18′02″N 2°15′34″W / 43.30056°N 2.25944°W / 43.30056; -2.25944 Greenland Plate The Greenland plate is a tectonic microplate bounded to the west by Nares Strait , a probable transform fault ; on the southwest by the Ungava transform underlying Davis Strait ; on the southeast by
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