The High Atlas, also called the Grand Atlas, is a mountain range in central Morocco, North Africa, the highest part of the Atlas Mountains.
The Toarcian is, in the ICS' geologic timescale, an age and stage in the Early or Lower Jurassic. It spans the time between 184.2 Ma and 174.7 ±0.8 Ma. It follows the Pliensbachian and is followed by the Aalenian.
In the geologic timescale, the Sinemurian is an age and stage in the Early or Lower Jurassic Epoch or Series. It spans the time between 199.5 ±0.3 Ma and 192.9 ±0.3 Ma. The Sinemurian is preceded by the Hettangian and is followed by the Pliensbachian.
The Pliensbachian is an age of the geologic timescale and stage in the stratigraphic column. It is part of the Early or Lower Jurassic Epoch or Series and spans the time between 192.9 ±0.3 Ma and 184.2 ±0.3 Ma. The Pliensbachian is preceded by the Sinemurian and followed by the Toarcian.
Lusitanosaurus is a genus of reptile from the Sinemurian stage of Early Jurassic of Portugal. It is the second example of the group from the Lower Jurassic of Europe and it is the oldest known dinosaur from the Iberian Peninsula. It is based on a large left maxilla with teeth that was lost in the fire at Museu Nacional de História Natural e da Ciência, Lisbon, in 1978.
Wilhelm Island is an island in the Svalbard archipelago. It is situated northeast of Olav V Land on Spitsbergen, in Hinlopen Strait. Its area is 120 km². About 33.5 % of the island is covered with ice. The island was named after Wilhelm I.
Leptonectes is a genus of ichthyosaur that lived in the Late Triassic to Early Jurassic. Fossils have been found in Belgium, Germany, Switzerland, Spain and the United Kingdom. The type species, L. tenuirostris, reached 4 metres (13 ft) long, while L. moorei reached 3 metres (9.8 ft) long; the largest species, L. solei, was approximately 5–6 metres (16–20 ft) long.
Psiloceratoidea is a superfamily of Early Jurassic ammonoid cephalopods proposed by Hyatt in 1867, assigned to the order Ammonitida. They were very successful during Hettangian and Sinemurian. Last of them, family Cymbitidae and genera Hypoxynoticeras and Radstockiceras survived into Early Pliensbachian.
The Aganane Formation is a Pliensbachian geologic formation in the Azilal, Béni-Mellal, Ouarzazate, Tinerhir and Errachidia provinces, central Morocco, being the remnant of a local massive Carbonate platform, and known mostly for its rich tracksites including footprints of thyreophoran, sauropod and theropod dinosaurs. This formation has been dated to the Pliensbachian stage of the Lower Jurassic, thanks to the find of the ammonite Arieticeras cf. algovianum, indicator of Middle Domerian in the upper zone, and lower delimitation by the foraminifers Mayncina termieri and Orbitopsella praecursor. The dinosaur tracksites are all located a few metres below the Pliensbachian-Toarcian limit, being coeval and connected with the lowermost layers of the continental Azilal Formation. The Aganane Formation was also coeval with the Jbel Taguendouft Formation and the Tamadout 1 Formation, all developed along a local "platform-furrow" in the Middle Atlas Mountains, that act as a barrier controlling the western border of the Jurassic Atlas Gulf. The nearshore sections, including both carbonate platforms and close to sea terrestrial facies where located on an isolated internal domain thanks to the control of the barrier, allowing the Aganane Formation to develop on a hot and humid climate, where a local algal marsh had intermittent progradations, intercalated with a layer of terrigenous continental origin. The ichnosites were developed in tidal flats and coastal deposits suitable to sea flooding.
Westphaliasaurus is an extinct genus of plesiosaur from Lower Jurassic deposits of Westphalia, northwestern Germany. It is known from a nearly complete and articulated skeleton missing the skull and about 38% of the upper neck vertebrae.
Cryonectes is an extinct genus of pliosaurid plesiosaurian known from the Early Jurassic of Normandy, northern France.
Lytoceratidae is a taxonomic family of ammonoid cephalopods belonging to the suborder Lytoceratina, characterized by very evolute shells that generally enlarge rapidly, having whorls in contact but mostly overlapping very sightly, or not at all.
The Hasle Formation is a geologic formation on the island on Bornholm, Denmark. It is of early to late Pliensbachian age. Vertebrate fossils have been uncovered from this formation. The type section of the formation is found at the south of the costal Hasle Town, and it is composed by rusty yellow to brownish siltstones and very fine-grained sandstones. The southernmost arch, Hvjdoddebuen, is not as fossil-bearing as the type unit in Hasle. The formation can be separated in two different petrographic types: type 1 sandstones are friable with layers and lenses of concretionary siderite and type 2 well-cemented sandstones. Both types where deposited in a relatively high-energy marine environment with a diagenetic pattern that demonstrates a close relation to various phases of subsidence and uplift in the tectonically unstable Fennoscandian Border Zone. Most of its deposition happened on a storm-dominated shoreface, with the exposed parts deposited in an open marine shelf within 1–2 km distance from the fault-controlled coastlines. However, recent works have recovered terrestrial fauna from it, including a footprint, suggesting easterly winds and low tide could have exposed the inner parts of the upper shoreface, and create long-lasting Floodplain-type environments. Field works since 1984 have shown a mostly hummocky cross-stratified deposition, with great complexity of the sediments that suggests very complicated and variable flow conditions, with Megaripples derived from storm events. Storms were frequent and the coastline faced a wide epeiric sea with a fetch towards the west of possibly 1000 kilometers. The Jamesoni–Ibex Chronozone in the Central European Basin represents a clear sea Transgression, due to the appearance of ammonites from Thuringia and southern Lower Saxony, showing a full marine ingression towards the west. This rise in the sea level is also measured in the north, as is proven by the presence of Uptonia jamesoni in Kurremölla and Beaniceras centaurus plus Phricodoceras taylori on the Hasle Formation. The whole Hasle Sandstones are a result of this rise in the sea level, where the marine sediments cover the deltaic layers of the Rønne Formation. The rise in the sea level is observed on palynology, as on the Hasle Formation Nannoceratopsis senex (Dinoflajellate) and Mendicodinium reticulaturn appear, indicating a transition from paralic and restricted marine to fully marine.
The family Dactylioceratidae comprises Early Jurassic ammonite genera with ribbed and commonly tuberculate shells that resembled later Middle Jurassic stephanoceratids and Upper Jurassic perisphinctids. Shells may be either evolute or involute.
Arminisaurus is a genus of pliosaurid plesiosaur that lived during the Lower Jurassic in present-day Germany. With Westphaliasaurus and Cryonectes, Arminisaurus is only the third plesiosaurian taxon that was described from the Pliensbachian stage. The holotype and only known specimen is a fragmentary skeleton, comprising an incomplete lower jaw, teeth, vertebrae and elements from the pectoral girdle and the paddles. The animal had an estimated body length of 3–4 metres (9.8–13.1 ft).
The Drzewica Formation is a geologic formation in Szydłowiec, Poland. It is Pliensbachian in age. Vertebrate fossils have been uncovered from this formation, including dinosaur tracks. The Drzewica Formation is part of the Depositional sequence IV-VII of the late lower Jurassic Polish Basin, with the IV showing the presence of local Alluvial deposits, with possible meandriform deposition origin, dominated in Jagodne and Szydłowiec, while delta system occurred through the zone of the modern Budki. The sequence V shows a reduction of the erosion in the Zychorzyn borehole of the Drzewica Formation, showing changes on the extension of the marine facies, where upper deposits change from Alluvial to Deltaic-Seashore depositional settings. VI-VII facies were recovered on the Brody-Lubienia borehole, with a lower part exposed on the village of Śmiłów that shows a small fall of the Sea level. The stathigraphic setting of the dinosaur tracks reported from the formation suggest a Seashore or Deltaic barrier. Body fossils reported include bivalves, palynology, fossil trunks, roots. Trunks of coniferous wood, especially Cheirolepidiaceae and Araucariaceae trees show the occurrence of vast coniferous forests around the tracksite. The association of forests and dinosaur megafauna on the Pliensbachian suggests also a colder and specially dry ecosystem. Drzewica deposits where in part to be a gigantic shore barrel, setting at the time where the Polish basin sea was at its lowest point. Other related units are Fjerritslev or Gassum Formation, Hasle & Sorthat Formation (Bornholm), upper Neringa Formation (Lithuania) and abandoned informal units in other regions of Poland: upper Sawêcin beds, Wieluñ series or Bronów series.
The Rotzo Formation is a geological formation in Italy, dating to roughly between 192 and 186 million years ago and covering the Pliensbachian stage of the Jurassic Period in the Mesozoic Era. Has been traditionally classified as a Sinemurian-Pliensbachian Formation, but a large and detailed dataset of isotopic 13C and 87Sr/86Sr data, estimated the Rotzo Formation to span only over the Early Pliensbachian, bracketed between the Jamesoni-Davoei biozones, marked in the Loppio Oolitic Limestone–Rotzo Fm contact by a carbon isotope excursion onset similar to the Sinemu-Pliens boundary event, while the other sequences fit with the a warm phase that lasts until the Davoei biozone. The Rotzo Formation represented the Carbonate Platform, being located over the Trento Platform and surrounded by the Massone Oolite, the Fanes Piccola Encrinite, the Lombadian Basin Medolo Group and Belluno Basin Soverzene Formation, and finally towards the south, deep water deposits of the Adriatic Basin. The also Pliensbachian Aganane Formation of Morocco represents a regional equivalent, both in deposition and faunal content.
The Sorthat Formation is a geologic formation on the island of Bornholm, Denmark and in the Rønne Graben in the Baltic Sea. It is of Latest Pliensbachian to Late Toarcian age. Plant fossils have been recovered from the formation, along with several traces of invertebrate animals. The Sorthat Formation is overlain by fluvial to lacustrine gravels, along with sands, clay and in some places coal beds that are part of the Aalenian-Bathonian Bagå Formation. Until 2003, the Sorthat Formation was included as the lowermost part of the Bagå Formation, recovering the latest Pliensbachian to lower Aalenian boundary. The Sorthat strata reflect a mostly marginally deltaic to marine unit. Large streams fluctuated to the east, where a large river system was established at the start of the Toarcian. In the northwest, local volcanism that started in the lower Pliensbachian extended along the North Sea, mostly from southern Sweden. At this time, the Central Skåne Volcanic Province and the Egersund Basin expelled most of their material, with influences on the local tectonics. The Egersund Basin has abundant fresh porphyritic nephelinite lavas and dykes of lower Jurassic age, with a composition nearly identical to those found in the clay pits. That indicates the transport of strata from the continental margin by large fluvial channels of the Sorthat and the connected Röddinge Formation that ended in the sea deposits of the Ciechocinek Formation green series.
Bocaconodon is an early mammaliaform genus that lived during the Pliensbachian of Mexico. The type and only species, Bocaconodon tamaulipensis, was named and described in 2008. It is known from a single specimen, a partial right dentary bone preserving two nearly complete molar teeth and the rear portion of a third molar. The specimen was found at the Huizachal Canyon locality, "a Pliensbachian floodplain siltstone in the La Boca Formation".
The Toarcian extinction event, also called the Pliensbachian-Toarcian extinction event, the Early Toarcian mass extinction, the Early Toarcian palaeoenvironmental crisis, or the Jenkyns Event, was an extinction event that occurred during the early part of the Toarcian age, approximately 183 million years ago, during the Early Jurassic. The extinction event had two main pulses, the first being the Pliensbachian-Toarcian boundary event (PTo-E). The second, larger pulse, the Toarcian Oceanic Anoxic Event (TOAE), was a global oceanic anoxic event, representing possibly the most extreme case of widespread ocean deoxygenation in the entire Phanerozoic eon. In addition to the PTo-E and TOAE, there were multiple other, smaller extinction pulses within this span of time.
