Triceratops Horned Dinosaur Fossil Bone Ceratopsid Ornithopod Cretaceous Collection (3)

Fossil Bone Triceratops Horned Dinosaur mm 18 x 20 x 9 Triceratops horridus Ceratopsid Ornithopod Herbivore Armored Quadruped Extinct Reptiles Mesozoic Cretaceous Collecting Paleontology Museum.

Beautiful collectible fossil specimen in very good condition. Probable frill section of the "shield" at the back of the head; a remarkable piece, with evident details of the spongy bone tissue structure or the grooves of blood capillarization, and the imprint of the dermal scales.
No restoration at all. Only a piece, as in photos.

Also available Fossil Bone of Triceratops in small plexiglas boxes or in lots, at this link.

The Triceratops (Ceratopsia, Ceratopsidae) was an ornitischian dinosaur quadrupedal, herbivorous, lived during the Maastrichtian (Late Cretaceous) in North America. It is part of the family of Ceratopsidae and is characterized by a semicircular collar bone and three horns. It was one of the last dinosaurs to appear before the extinction of the limit K-T.
The numerous discoveries of remains took place from the end of the nineteenth century, especially skulls, western United States and southern Canada, has given rise to a real "bloom" species described, categorized by size and the shapes of horns and the configuration of the characteristic collar bone.
The curious aspect of this large quadrupedal herbivore (it was up to 9 meters long, 3 feet tall and weighed perhaps 8 tons) was of course given by the skull length of up to 2.30 meters, characterized by a collar bone that was projected to ' back to protecting the neck and shoulders, the skull of T. was also topped by two long supraorbital horns, which made him look very menacing. A third horn, smaller, was located above the nostrils. There has been much speculation concerning the role played by the horns and flashy neck. The most credible is that they were used both to defend themselves from predators in the fighting between males, some fossil skulls, in fact, been wounded and needling that appear to have been inflicted by their horns. The large collar, in addition, also served as controller since it appeared very vascularized, which is full of a dense network of capillaries, in addition, also in the latter may have been anchored to the powerful jaw muscles with its beak.
Until recently, the T. was considered to belong to Ceratopsia with short neck, or Centrosaurinae, given the relative brevity of the structure. In fact, it seems more likely that this animal was a Casmosaurinae (or long-necked Ceratopsia) specialist, given the rather long squamosal bones. The collar, unlike all other Ceratopsia, was devoid of openings, providing a more complete protection. Perhaps T. was closely related to the small Avaceratops, with similar characteristics.
A recent study conducted by the famous paleontologist John Horner on fossil skulls and numerous specimens of T. and Torosaurus attempted to demonstrate that the T. was the f sub-adult form of Torosaurus. If confirmed, this would lead, according to rules established by the International Code of Zoological Nomenclature, the disappearance of taxa "torosaurus" to the principle of priority in how the genus Triceratops was described in 1889 before Torosaurus described in 1891. What more convincingly refute the theory of Horner, is the fact that the biggest skeleton of Triceratops found to be larger than Torosaurus, although the latter has a much larger skull. Another hypothesis is that Triceratops and Torosaurus may actually be the two sexes of the same species, and the difference in size and structure of the skull would then be attributable to sexual dimorphism hypothesis put forward in 1986 by John Ostrom and Peter Wellnhofer.