Where was the fossil found?

The specimen comes from a quarry of limestone some 20 km south of the desert castle of Kharraneh. In this quarry, in the area of Wadi Ed-dab'i, fragments of bones of large vertebrate are found, including fish up to 150 cm long. A good specimen of such a fish is at display in the showroom of the Natural Resource Authority in Amman. The stone of this quarry also contain ammonites a very common fossil of an ancient "extinct calamari". (As the one published in Al-Ra'i on May 18).

Wadi Ed-dab'i has been surveyed by Jordan's Natural Resource Authority, which published a report with a map of this area (Bulletin 42) in 1998.

Most of the fossils in this location are found inside the large boulders that have the natural shapes of slightly flattened spheres. These boulders, which the geologists call "concretions", are the source of much of the pinkish stone now used in buildings of Amman. Fragments of vertebrate fossils as well as ammonites are found and sometimes ignored, to end-up in the walls of some house without much fuss.

The vertebrate limb, as scientifically should be referred to, can be dated according to the layer from which these boulders come from. The NRA has identified this layer as "Muwaqqaq Chalk Marl Formation" MCM as it appears for short on their maps. This layer dates to the Maestrichtian- Paleocene age, which translates to 71.3 to 55 million years ago.

 

The anatomy

Looking the specimen, and by comparing the bone structure with limbs of land vertebrate (dinosaurs and other animals, even to living species) the first conclusion that could be made is that such a limb cannot support the weight of a large animal on land; specially not with those long "fingers". We learn from the evolution of vertebrae, that bone structures evolve to the function it carries, and, for land animals, limbs evolve into robust short-fingered designs to withstand the physical strains of the landscape out of the water. This is why most of Dinosaurs limbs have three or four relatively short fingers that give their legs qualities similar to those of birds, which is logical, since dinosaurs and birds are proving to be closely related.

In this fossil the bone structure calls for the function of a paddle more than that of a leg or an arm. This paddle limb makes it very difficult for this animal to leave water as we all now how uncomfortable for a human to walk on the ground with diving flaps.

Anatomy of the Jordanian Specimen
(front left limb?)
1- ula
2- intermedium

3- radiale

4- ulna
5- radius
6- humerus

 

Candidates

Now we have an animal with flaps and we have an age given by the NRA to the stone (71.3 to 55 million years ago). We must add one more fact to help narrowing down the dates. The mass-extinction that ended the life of 75% of all animal species, which was caused by a meteorite, the size of Amman (10 kilometers across), that struck the earth near the village of Chicxulub on the cost of Mexico, This great impact caused dust, smoke and soot (which reached Jordan and deposited the K-T boundary, as geologists call it, and which in now being identified in several locations in Jordan) The impact resulted in blocking the sun, causing destruction of habitat and interruption of food chains, a situation that the earth took some 2.5 million years to recover from. It is also, still, the most credible explanation of the extinction of the dinosaurs, the ammonites and many other reptiles such as the one from which this Jordanian specimen comes from. This makes it easier to assume that this reptile lived before or slightly after the devastating meteor.

With This mass-extinction 65 million years ago, the dating of this animal can be narrowed down to Maestrichian (71.3 to 65.4 million years ago) towards the end of the Mesozoic period. This brings four candidates that this limb might have belonged to. All the 4 are Mesozoic marine reptiles and have the complicated names as follows:

Ichthyosaur 3 meter long

Long-necked plesiosaur 12 meter long

Short-necked plesiosaur 3 to 4 meter long

Mosasaur 2 to 10 meter long

Which Animal

By comparing the Jordanian specimen with other specimens around the world the best identification would be within the family of the Mosasauridae. There are several species of mosasaurs (30 to 40) found all over the world (America, Africa, New Zealand, and Europe) This animal would have measured some 7 to 9 meters in length if the limb is one meter long as mentioned in the article in Arabic.

The name Mosasaur means " Meuse Reptile" following name of the location where the first such animal was discovered, around the Meuse River near Maastrict in the Netherlands, around 1770 to 1780 by Dr. C. K .Hoffmann . Eventually the specimen was called Mosasaurus hoffmanni., after a big custody battle involving more than one country. The Mosasaur was one of the first fossils to attract public attention. In that early discovery, in the Netherlands, the landowner won a court case against Hoffmann, but the fossil was eventually ransomed for 600 bottles of wind to an invading French army and was sent to France.

A mosasaur is a water reptile closely related to snakes. It ate fish, ammonites, smaller mosasaurs, and birds. These powerful reptiles were at the top of the food chain, in seas full of marine turtles, huge fish, and sharks. They gave life birth to their young and because they were air-breathing reptiles, they had to surface periodically to breathe. They swam close to the surface of the oceans all over the world.

When this animal was alive, Jordan was under warm tropical water. It was, then, still part of Africa and much closer to the equator, in a location around what is now Sudan. There was no Jordan Valley, no Red Sea and our current location was probably occupied by southern China. We have to imagine continents as emerging and submerging from water and constantly drifting like floating foam on the surface of a ball of molten rocks.

 

 

Jordanize it

This specimen is important to Jordan. It can help placing Jordan on the map of fossil enthusiasts as well as professional paleontologists. A professional paleontologist must verify the initial identification mentioned above. If this animal proves to add a new sub-family to the Mosasauridae, then it should be given the name " Jrdanosaur" or " Dab'isaur" or " Mosasaurus dab'i" (the lizard of Wadi Ad-dab'i)

It should, whit the flying dinosaur now at Jordan University, become part of a Natural History Museum. A Museum that will help us to understand the Jordanian landscape, beyond the limited vision of Jordan as a big quarry of natural resources.

 

To avoid commercial exploitation, the exact location can be given only for scientific purposes. 

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