Aptian is an age in the geologic timescale or a stage in the stratigraphic column. It is a subdivision of the Early or Lower Cretaceous epoch or series and encompasses the time from 125.0 ± 1.0 Ma to 112.0 ± 1.0 Ma (million years ago), approximately. The Aptian succeeds the Barremian and precedes the Albian, all part of the Lower/Early Cretaceous. [1 ]
The Aptian partly overlaps the upper part of the regionally used (in
western Europe) stage Urgonian.
Stratigraphic definitions [ edit ]
The Aptian was named after the small city of
Apt in the Provence region of France, which is also known for its crystallized fruits. The original type locality is in the vicinity of Apt. The Aptian was introduced in scientific literature by French palaeontologist Alcide d'Orbigny in 1840.
The base of the Aptian stage is laid at
magnetic anomaly M0r. A global reference profile for the base (a GSSP) had in 2009 not yet been appointed. The top of the Aptian (the base of the Albian) is at the first appearance of coccolithophore species in the stratigraphic record. Praediscosphaera columnata
Subdivision [ edit ]
Tethys domain, the Aptian contains eight ammonite biozones:
Sometimes the Aptian is subdivided in three substages or subages:
Bedoulian (early or lower), Gargasian (middle) and Clansayesian (late or upper).
Lithostratigraphic units [ edit ]
Antlers Formation, Cedar Mountain Formation, Cloverly Formation, Elrhaz Formation, Jiufotang Formation, Little Atherfield, Mazong Shan, Potomac Formation, Santana Formation, Twin Mountains Formation, Xinminbao Group, Yixian Formation
Palaeontology [ edit ]
† Ankylosauria of the Aptian
Cedar Mountain Formation, Utah, USA
Ulansuhai Formation, Inner Mongolia, China
Yixian Formation, Liaoning, China Nodosaurid with ventral armor plating
Bungil Formation, Queensland, Australia Small (1 meter long) primitive ankylosaur
Cloverly Formation, Wyoming, Montana, Utah, USA A medium-sized nodosaurid, measuring about 5 meters (16.5 ft) long,
Sauropelta had a distinctively long tail which made up about half of its body length. Its neck and back were protected by an extensive bony body armor including characteristically large spines
Birds (avian theropods) [ edit ]
†Choristoderans [ edit ]
Mammalia [ edit ]
Mammals of the Hauterivian
several species from Hauterivian to
Albian Spain, Mongolia
Yixian Formation, Liaoning, China A long-tailed, nocturnal tetrapod (with prensile fingers and toes) which hunted insects, its food, during the night
Yixian Formation, Liaoning, China The largest mammal known from the Cretaceous period of the Mesozoic, and the one for which there is the best evidence that it fed on dinosaurs.
Flat Rocks, Victoria, Australia The earliest known monotreme.
Yixian Formation, Hebei, China A small mammal, barely 13 centimetres (5 inches) long. It was lightly built and fed on insects, worms and other invertebrates, probably hunting at night. Like most early mammals, Yanoconodon had short, sprawling legs and claws that were most likely used for burrowing underground or digging
† Ornithopoda of the Aptian
Dinosaur Cove, Victoria, Australia 2–3 meters long hypsilophodont
Quantou Formation, Jilin, China As a small basal ornithopod, Changchunsaurus would have been a swift bipedal herbivore, feeding close to the ground.
Bernissart, Belgium; ?England; ?Germany A lightly constructed iguanodont, about 6 meters long (20 ft), estimated to weigh about 1 ton
Mazong Shan, Gansu, China Primitive hadrosaur or iguanodont
Worldwide distributed, type genus of the Iguanodontia. 10 meters long
9 meters long heavily built Iguanodont
Atherfield, England, UK formerly known as
Lakota Formation, South Dakota, USA A genus intermediate between
Camptosaurus and more derived iguanodonts.
Echkar Formation, Niger 7 meters long hadrosauroid, possibly with a sail on the back
Cedar Mountain Formation, Utah A genus of advanced iguanodont
1.8 meter long hypsilophodontid
Xinminbao Group, Gansu, China A hypsilophodontid or other basal ornithopod, Siluosaurus would have been a bipedal herbivore.
Cloverly Formation, Wyoming and Montana, Antlers Formation, Oklahoma, Twin Mountains Formation, Texas, USA 8 meters long early iguanodont
Purgatoire Formation, Colorado, USA An iguanodont described as intermediate in derivation between
Camptosaurus and Iguanodon
Cloverly Formation, Montana, USA Hypsilophodont
† Plesiosaurs of the Aptian
Kansas, USA; Colombia
A pliosaur that grew to around 10 meters in length, it represents the last known occurrence of a pliosaur in North America.
Paja Formation, Colombia
8 meters long elasmosaurid
Boyaca, Colombia Among the largest pliosaurs, body-length estimates put the total length of Kronosaurus at 9–10 meters
Relatively small cryptocleidid, around 2.5 m long, identified by the three crest-ridges on its skull.
† Sauropods of the Aptian
Itapecuru Formation, Maranhão, Brazil
A genus of 12 meters long diplodocoid.
Arundel Formation, Maryland, USA A large titanosaur, adults are estimated to have been more than 9m high and 15m to 18m long.
Napai Formation, Guangxi, China
Probably a basal titanosaur, known by fragmentary postcranial remains
Albian Sahara Desert
Seems to be a very primitive sauropod. Unlike other Cretaceous sauropods, Jobaria had spoon-shaped teeth.
Titanosaurid which fossils consist solely of parts of a lower mandible and a few teeth
A basal titanosaurid
One of the few titanosaurs for which skull material has been found
Elrhaz Formation, Niger Diplodocoid dinosaur, one of the most common genera found in the rich fossil vertebrate fauna of the Elrhaz Formation
Twin Mountains Formation, Texas, USA A basal titanosauriform
Antlers Formation, Oklahoma, USA The last known giant brachiosaurid; extrapolations indicate that the head of Sauroposeidon could reach 17 m in height, making it the tallest known dinosaur. With an estimated length of 30 m and a mass of 36–40 MT it also ranks among the longest and heaviest.
Grès Supérior Formation, Laos
A basal titanosaur, known from the remains of two or three individuals.
Cedar Mountain Formation, Utah, USA A titanosaur, known from an incomplete skeleton of an adult and a juvenile
† Stegosauria of the Aptian
Wuerhosaurus homheni †
Xinjiang, Inner Mongolia, China
7 meter long stegosaurid
† Non Avian Theropods of the Aptian
Texas, Oklahoma, ?Maryland, USA
Likely an apex predator, up to 12 meters long. Classification disputed (Carcharodontosaurid or Allosaurid)
Jiufotang Formation, Liaoning, China Small (90 centimeters long feathered dromeaosaurid, possibly the same species as
Cloverly Formation, Montana and Wyoming, Antlers Formation, Oklahoma, Potomac Formation, Maryland, USA 3–4 meters long carnivorous dromaeosaurid
Chubut Province, Argentina
Yixian Formation, Liaoning, China Large (1.8 meter long) compsognathid
Elrhaz Formation, Niger Earliest-known abelisaurid
Isle of Wight, England, UK
7.5 meters long allosaurid
Yixian Formation, Liaoning, China Primitive oviraptosaur, possibly synonymous with
Jiufotang Formation, Liaoning, China Caudipterid oviraptosaur
1 meter long troodontid
1.20 meter long compsognathid, fossilized with traces of color pigmentation in its feathers
12 meters long spinosaurid
Chubut Province, Argentina
12 meters long carcharodontosaurid
The largest known dromaeosaurid
References [ edit ]
Literature [ edit ]
External links [ edit ]