Breviparopus
Encyclopedia
Breviparopus is the name given to an ichnogenus of dinosaur
Dinosaur
Dinosaurs are a diverse group of animals of the clade and superorder Dinosauria. They were the dominant terrestrial vertebrates for over 160 million years, from the late Triassic period until the end of the Cretaceous , when the Cretaceous–Paleogene extinction event led to the extinction of...

, having been made by an unknown genus
Genus
In biology, a genus is a low-level taxonomic rank used in the biological classification of living and fossil organisms, which is an example of definition by genus and differentia...

 of sauropod. As an ichnogenus, the taxon is represented by (and named for) a ninety-metre-long series of fossil
Fossil
Fossils are the preserved remains or traces of animals , plants, and other organisms from the remote past...

 tracks, or ichnite
Ichnite
An ichnite is a fossilised footprint. This is a type of trace fossil. Over the years, many ichnites have been found, around the world, giving important clues about the behaviour of the animals that made them...

s, found in the spring of 1979 in the Atlas Mountains
Atlas Mountains
The Atlas Mountains is a mountain range across a northern stretch of Africa extending about through Morocco, Algeria, and Tunisia. The highest peak is Toubkal, with an elevation of in southwestern Morocco. The Atlas ranges separate the Mediterranean and Atlantic coastlines from the Sahara Desert...

 of present-day Morocco
Morocco
Morocco , officially the Kingdom of Morocco , is a country located in North Africa. It has a population of more than 32 million and an area of 710,850 km², and also primarily administers the disputed region of the Western Sahara...

. At the time, this area would have been part of the splitting Gondwana
Gondwana
In paleogeography, Gondwana , originally Gondwanaland, was the southernmost of two supercontinents that later became parts of the Pangaea supercontinent. It existed from approximately 510 to 180 million years ago . Gondwana is believed to have sutured between ca. 570 and 510 Mya,...

 supercontinent
Supercontinent
In geology, a supercontinent is a landmass comprising more than one continental core, or craton. The assembly of cratons and accreted terranes that form Eurasia qualifies as a supercontinent today.-History:...

.The animal that produced the Breviparopus tracks is rumored to be one of the largest dinosaurs, though its exact size has been the subject of much debate.

Fossil material and age

The combined length of the tracks of the foot and hand measured 115 centimetres (45.3 in), and they were 90 centimetres (35.4 in) in width. They are commonly dated to the Jurassic
Jurassic
The Jurassic is a geologic period and system that extends from about Mya to  Mya, that is, from the end of the Triassic to the beginning of the Cretaceous. The Jurassic constitutes the middle period of the Mesozoic era, also known as the age of reptiles. The start of the period is marked by...

 period (approximately 160–175 million years ago), though they are more likely from the early Cretaceous, roughly 130-120 million years ago. They were first described by Jean-Michel Dutuit and Achmed Ouazzou in 1980.

Size of trackmaker

The size, weight, and even family
Family
In human context, a family is a group of people affiliated by consanguinity, affinity, or co-residence. In most societies it is the principal institution for the socialization of children...

 tree of the animal that made Breviparopus tracks is unknown, but a great deal of speculation has arisen about this animal. Length estimates as great as 48 metres (157.5 ft) have been given in popular books such as Guinness World Records
Guinness World Records
Guinness World Records, known until 2000 as The Guinness Book of Records , is a reference book published annually, containing a collection of world records, both human achievements and the extremes of the natural world...

, though these were based on the misconception that the 115 centimetres (45.3 in) figure was based on a single footprint, not the combined length of the fore and hind feet.

In reality, the trackmakers of Breviparopus were likely somewhat smaller than this. The actual prints are 90 centimetres (35.4 in) wide and about as long. The feet were probably even larger than 90 centimetres (35.4 in) wide since the edges of the prints are collapsed. This would result in an animal roughly 110 to 120 ft (33.5 to 36.6 m) long, assuming proportions similar to Giraffatitan
Giraffatitan
Giraffatitan, meaning "giraffe titan", is a genus of sauropod dinosaur that lived during the late Jurassic Period . It was originally named as an African species of Brachiosaurus...

. Earlier estimates that the prints were only 50 centimetres (19.7 in) wide, no larger than the feet of Diplodocus
Diplodocus
Diplodocus , or )is a genus of diplodocid sauropod dinosaur whose fossils were first discovered in 1877 by S. W. Williston. The generic name, coined by Othniel Charles Marsh in 1878, is a Neo-Latin term derived from Greek "double" and "beam", in reference to its double-beamed chevron bones...

, have since been shown to be incorrect.

Taxonomy

Traditionally, Breviparopus has been regarded as a brachiosaur, which seemed to correspond with the fact that "Brachiosaurus" nougaredi, another giant brachioaur of near-mythic proportions known from a colossal sacrum
Sacrum
In vertebrate anatomy the sacrum is a large, triangular bone at the base of the spine and at the upper and back part of the pelvic cavity, where it is inserted like a wedge between the two hip bones. Its upper part connects with the last lumbar vertebra, and bottom part with the coccyx...

, was discovered not too far from Morocco, in Early Cretaceous deposits in Wargla, Algeria. Since no actual bones of Breviparopus have been identified, it is difficult to say with certainty whether the trackmaker was a diplodocid
Diplodocid
Diplodocids, or members of the family Diplodocidae , are a group of sauropod dinosaurs. The family includes some of the longest creatures ever to walk the earth, including Diplodocus and Supersaurus, which may have reached lengths of up to .-Description:While still massive, when compared to the...

, titanosaur
Titanosaur
Titanosaurs were a diverse group of sauropod dinosaurs, which included Saltasaurus and Isisaurus. It includes some of the heaviest creatures ever to walk the earth, such as Argentinosaurus and Paralititan — which some believe have weighed up to 100 tonnes...

 or brachiosaur. All that can be said for certain, according to Michel Monbaron and colleagues, is that Breviparopus is quite distinct from the prints made by Atlasaurus
Atlasaurus
Atlasaurus was a moderately large genus of sauropod dinosaur from Middle Jurassic beds in North Africa.-Discovery and species:Atlasaurus was discovered by Monbaron, Russell & Taquet in 1999...

. However, the presence of a small medially directed thumb-claw print makes it likely the animal was a brachiosaur, since they have small thumb claws at ground level (as opposed to diplodocids and camarasaurids, whose thumb metacarpals are short and hold their thumb claws off the ground), and the narrow-gauge stance also fits with a brachiosaur body shape - in the Early Cretaceous, the dominant sauropods were wide-bodied titanosaurs, and deep-bodied brachiosaurs which had more narrowly spaced legs - therefore the narrow gauge of the Breviparopus prints favors a brachiosaurid diagnosis (this seems to be corroborated by the sacrum of "Brachiosaurus" nougaredi, which is unusually narrow for its length even by brachiosaur standards). It is also worth noting that the bone fossil record from the Middle Jurassic
Middle Jurassic
The Middle Jurassic is the second epoch of the Jurassic Period. It lasted from 176-161 million years ago. In European lithostratigraphy, rocks of this Middle Jurassic age are called the Dogger....

, according to C.A. Meyer is rather more incomplete and fragmented than the fossil record of dinosaur tracks.

External links

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