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Scleromochlus in the Flesh
(This image erroneously assumes that Scleromochlus had a soft, fur-like integument as known for pterosaurs and some theropod dinosaurs, when in fact it was scaled, more to crocodilian and basal dinosaurian anatomy, as shown in the near-dinosaur Lewisuchus.)

This page is initially intended to offer these skeletons and a detailed explanation of their creation. In the future, more detail may be presented on them and the taxon they represent.

Scleromochlus taylori is a small, slender animal, graceful on long hind legs, possibly capable of both bipedal and quadrupedal locomotion; it was fairly small, measuring about 186 mm in length, or about 4.3 inches, of which 34.4 mm was head (about ¹/₅ body length), and hailed from the Upper Triassic (upper Carnian) Lossiemouth Formation in Lossiemouth, just north of Elgin in northern Morayshire, Scotland (UK). The holotype is BMNH R3556, a partial skeleton preserved in negative form (only as impressions) on sandstone, with a partial, damaged skull and missing distal tail. Other specimens include BMNH R3557, which was acquired by the NHM (Natural History Museum; current designation of the BMNH [British Museum of Natural History], where all collections retain the former designation) along with the holotype; BMNH R3146, including two animals designated 3146A and 3146B, which represent a larger individual (A) with incomplete limbs and extensive dorsal scalation preserved in position as well as ribs, and a smaller (B) with more complete limbs and nearly perfect dorsal sacrum and hips showing their relation to the legs and remainder of the vertebrae; BMNH R3914, a very partial skeleton showing the position of various dorsal ribs, but rather fragmentary otherwise; BMNH R4823 & BMNH R4824, separately catalogued part and counterpart of the same individual, primarily comprising an incomplete skeleton that displays the armor particularly well, as well various other disarticulated elements in near-natural position; BMNH R5589, representing a highly disarticulated specimen from the "West" Lossiemouth Quarry, rather than the "East" Lossiemouth Quarry as in all other specimens, preserving a skull with possible long vomers in view; this specimen is without a counterslab, unfortunately. All known specimens are preserved on either their bellies or backs (depending on orientation of the animal on the main slab -- the case ambiguous in BMNH R5589 given the absence of a counterslab).


Figure 1: Map of Scotland, showing the location of Lossiemouth (in the northeast, on the coast of the North Sea and the Moray Firth).
A lateral observation is a task of some guess work, based on the orientation of known specimens, though fortunately this is limited only to the general depth of the skull and shapes of the vertebral centra, as well as length and breadth/depth of the ribcage. The skeletons offered on this page afford the viewer four possible views of the skeleton: top, side, front, and back. Nearly the entire skeleton is known, missing largely the distal tail, most haemal arches, and the complete hand and foot; the last (fourth) pair of sacral ribs are not known, but are considered to be present, and are illustrated as missing. The foot is shown complete, as are the haemal arches in series, along with cervical ribs, and the dorsal and belly scalation are omitted though present in some specimens. The internal palatal bones and hyoid are shown in grey, though much of this is present, and the quadrate is not actually present in complete, so its shape is inferred as a simple structure, but the length of the jaw and the lower temporal bones (jugal and quadratojugal) as well as the lower jaw itself, show that it was an angled element. The fewest assumptions on shapes and identifications were made, largely following the work of Benton to permit reconstruction. In the front and back representations, the scleral rings (the bony ring that surrounds the eyes, composed of multiple small, quadrangular plates) are artificial and there is no evidence of them or of the vomer at present. The medial view of the lower jaw and the rest of the braincase are artificial, and some resemblance to Lewisuchus admixus is not intended though peculiar. Previous restorations of Scleromochlus, namely those that endorsed in earlier works including Norman's Illustrated Encyclopedia of Pterosaurs (1991) the presence of a hind-leg membrane to the tail, or uropatagium, are based on superficial similarities to Sharovipteryx, these features not actually present on the slab in actuality, and purely conjectural. The shape of the femur indicates the more medial orientation of the head, implying loss of any true ability to splay the leg sideways in order to make any effective use of the leg as a "wing" analogue, as proposed for Sharovipteryx.

Figure 2: The top and side views of the two most complete specimens, of which BMNH R3556 is the largest on most recurrent material. Scale bar as read is 2 cm.


Figure 3: The front (left) and rear (right) views of the two most complete specimens. The scale is to be read as identical to Figure 1 as the figure is scaled to the same dimensions. In the rear view, the forelimbs are not included for simplicity's sake.

• Benton, M.J. 1999. Scleromochlus taylori and the origin of dinosaurs and pterosaurs. Philosophical Transactions of the Royal Society of London, B 354: 1423-1446.
• Woodward, A.S. 1907. On a new dinosaurian reptile (Scleromochlus taylori gen. et sp. nov.) from the Trias of Lossiemouth, Elgin. Quarterly Journal of the Geological Society of London 63: 140-146.

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My appreciation can be found here. This Page and all other Qilong Pages are the © (1997-2001) property of Jaime A. Headden. Gain my permission to use any images or source material, but references are free for all.