Sunday, April 03, 2016

Many Worlds of April. Saga of the Jurassic. Fruitadens

There is a common perception among the lay population that all dinosaurs were of gigantic dimensions. This theory was stood on its head with the unearthing and subsequent identification of the fossils of the Fruitadens Haagarorum

Etymology
The word Fruitadens is often literally translated and taken to mean “fruit tooth” or “teeth like fruits”. The truth is that the Fruitadens Haagarorum is fundamentally named after the Fruita fossil region of Colorado, United States of America where its fossils were first excavated at the base of the Brushy Basin Member of the Morrison Formation. The creature's full name is Fruitadens Haagarorum. The appellation haagarorum is a tribute to Paul Haaga Jr, President of the Board of Trustees of the Natural History Museum of Los Angeles County where the fossils were stored after discovery..

Finding the Fruitadens

The fossils of the Fruitadens Haagarorum were discovered nearly four decades ago, largely by chance, by a team of dinosaur hunters led by George Callison. The fossils discovered consisted of the skulls, vertebrae, arms and legs of four individual dinosaurs and were recovered from the Fruita Paleontological Area, Colorado, USA. The fossils were housed at the Natural History Museum of Los Angeles County. The enormity of the finding was not immediately recognized. Fossils of the Fruitaden Haagarorum have not been recovered at any other location.
Identification of Fruitadens

Identification took more than 30 years after the discovery of the fossils and their storage in the Natural History Museum of Los Angeles County. In retrospect, it is more than a little surprising that the fossil specimens of Fruitadens lay unidentified in the Natural History Museum of Los Angeles County for so long before being meticulously examined by paleontologists. What they found created worldwide ripples: a tiny, late Jurassic dinosaur. The species was identified and named by an international team of scientists, led by Dr. Richard Butler, Bavarian State Collection for Paleontology, Munich, Germany, and also included Dr. Luis Chiappe, Director of the Natural History Museum Dinosaur Institute. The fossil fragments which were put under the microscope were skull fragments and vertebrae along with jaws and limb bones.
Dr. Luis Chiappe is overseeing construction of a detailed, full-scale model of the animal. Fruitadens is a late surviving member of the basic dinosaur family heterodontosuridae, and is the first member of its group to be described from North America.
History of Fruitaden

The habitat of Fruitadens Haagarorum was the woodlands of North America where it flourished during the late Jurassic period (early tithonian) approximately 150 million years ago. The lightweight build of Fruitadens means that it would have been a very fleet footed runner, easily able to travel speedily across the forest floor while maintaining running speed; racing between the legs of the generally much larger dinosaurs. Paleontologists have expressed opinions that Fruitadens Haagarorum thrived for more than 100 million years which is a very long time when assessed by peer standards. This span of survival is remarkable given that it lived right at the base of the dinosaur evolutionary tree. The anatomy and body size of Fruitadens suggest that it was an omnivore. This finding sheds new light on the dietary diversity in the dinosaur family. Paleontologists have gradually come around to the view that late Jurassic and early Cretaceous heterodontosaurids were smaller and less restricted in their dietary consumption compared to late Triassic and early Jurassic heterodontosaurids. There is considerable speculation that it was this adaptation to an omnivorous diet which may account in part for the remarkable 100 million year long survival of the species.

Physical features of Fruitadens
An adult Fruitadens Haagarorum was around 2 feet long and weighed about 1-2 pounds. It is one of the smallest known dinosaurs ever discovered. Up until 2010, the only known small dinosaurs were the theropods. With the discovery of the Fruitadens Haagarorum, paleontology is left wondering about the limits of dinosaur size. Dinosaurs can range in size, from 2-pound animals like Fruitadens to creatures weighing 50 tons or more like the huge dinosaurs made famous by fiction and Hollywood blockbusters.
The finding that Fruitadens is unique is borne out by its distinctive array of teeth and the structure and positioning of its hind legs. Detailed studies have led to a conclusion  that the jaws of heterodontosaurids, including Fruitadens, which survived longer, were adapted for biting at obtuse angles. In contrast, the jaws of the older heterodontosaurids, were apposite for strong jaw operationally at acute angles. There is much paleontological support for the view that that Fruitadens  processed its food by a relatively uncomplicated process of puncturing it and, thereafter, crushing it. The Fruitadens had a set of teeth somewhat like that of canines and while there is evidence that some dinosaurs belonging to its family sported hair along the back, there is no evidence to suggest that such was the case with the Fruitadens Haagororum.
These findings suggest that Fruitadens was an biological omnivore, consuming plant material and possibly insects or other invertebrates with equal comfort.

Classification of Fruitaden
Fruitadens has been classified as an ornithopod, and is believed to have been a much smaller relative of heterodontosaurus. Fruitaden belonged to heterodontosaurids, which were one of earliest species of dinosaurs to have evolved. However, Fruitadens Haagarorum is a more recent or shall we say a latterly evolved member of this family. Heterodontosaurids also had the similar unusual combination of teeth like the Fruitadens Haafarorum. The more recent Fruitadens evolved to be smaller and have a more generalized and varied diet. The accepted classification of Fruitadens is Animalia, Chordata, Sauropsida,  Dinosauria, Ornithischia, Heterodontosauridae, Fruitaden.

Future discoveries
The Morrison Formation where the fossils of the Fruitaden Haagarorum were discovered covers an area of 600,000 square miles though only a small portion of it has been explored. Fossil experts have been studying the Morrison Formation for more than a century.  Dozens of dinosaur species have been discovered there and there is every possibility that there may be many such treasures lying unearthed. Till then the world will celebrate the discovery of Fruitadens Haagarorum.

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