Bennett—Rhamphorhynchus wings
deltopectoral crest of the left humerus are visible in the angle between the skull and neck whereas the rest of the humerus, antebrachium, carpus, and metacarpus are presumably buried in the matrix beneath the skull and body, and the wingfinger is extended to the left, roughly perpendicular to the trunk. A deep excavation into the matrix exposes the distal two-thirds of the left WP1 as it rises through the matrix to the specimen’s main bedding plane. The left wingfinger extended beyond the margin of the slab such that the distal half of WP2 and WP3–4 are missing. Wing phalanges 1–4 of the right wing are 95, 75, 74, and 80mm long, respectively, and the estimated wingspan of the specimen in life using my standard method is 86 cm, thus ~85% the size of the Zittel wing. The hindlimbs are presumably buried in matrix except for the pedes that are visible adjacent to the pelvis. The specimen preserves impressions of the dactylopatagia
and the lateralmost parts of the plagiopatagia of both wings; that of the right wing extends from behind WP1 to the wing tip and that of the left from behind WP1 and 2. When the specimen sank to the bottom of the lagoon, it came to lie with the ventral surface of its trunk on the substrate, the right wing under the
body with its ventral surface on the substrate, and the left wing flipped over to lie over the body with the brachium through metacarpus folded compactly, the wingfinger extended to the left, and the dorsal surface of the wing on the substrate. As a result, the right wing impression is preserved such that it appears to be exposed in ventral view, whereas the left wing impression is preserved such that it appears to be exposed in dorsal view. The proximalmost part of the impression of the right wing was on a thin layer of matrix that covered the posterior trunk and feet. The matrix was prepared away in places to expose the bones, but the soft tissue impression is still preserved on the matrix between those bones. The right dactylopatagium is partially folded as indicated by several deep furrows. The brachiopatagium has a sharply pointed tip and the chord as
preserved is about 13, 40, and 50mm behind the third through first IP joints, respectively. The left dactylopatagium seems not to have been folded significantly and has a chord as preserved of ~55mm behind the first IP joint and the trailing edge is gently convex. However, because the brachium, antebrachium, and metacarpus were folded the plagiopatagium was lax and its lateralmost part was folded over the proximal part of the dactylopatagium. The deep excavation around the top of the skull probably cut away the proximalmost part of the soft tissue trace of the left wing. Viewed from a moderate distance the left wing exhibits the wing skeleton and a series of undulations and linear features in the dactylopatagium and the partially folded right wing exhibits more prominent folds. On closer examina-
tion and particularly under low angle illumination tool marks, fine striae, and the retrophalangeal wedge are visible. These features are described below, and with the exception of the undulations and tool marks, they were mapped and are shown in Figure 6.
Undulations and folds.—There is a series of gentle undulations with a wavelength of ~3mm along the proximal part of the trailing edge of the left dactylopatagium; however, neither wing exhibits the series of undulations parallel to the wingfinger seen in the Zittel wing. The left wing exhibits three linear features
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that are not folds but seem to be fold lines corresponding to those of the Zittel wing (Fig. 6.1). Fold Line B is visible behind the retrophalangeal wedge extending posterolaterally in an arc to near the trailing edge behind the first IP joint and its course suggests that its anteromedial end was near the MCP joint. Fold Line C is visible behind WP2 and its course suggests that its anteromedial end was near the proximal end of WP1 and its posterolateral end was near the trailing edge behind the second IP joint. A third fold line that presumably is Fold Line D lies anterior to Fold Line C with its anteromedial end near the first IP joint. There is a fold in the retrophalangeal wedge that extends anteromedially from where Fold Line D intersects the posterior margin of the retrophalangeal wedge. Based on the pattern of the Zittel wing, a Fold Line A might be expected near the proximal end of the impression; however, no evidence of one was found. The right wing is partially folded and exhibits several folds
as prominent furrows that also seem to correspond to the fold lines of the Zittel wing (Fig. 6.2). Fold Line B is visible for a short distance close to the trailing edge and ends behind the middle of WP2. Fold Lines C and D seem to be present but are disturbed at mid-chord by spanwise extraneous folds, one that is behind the proximal three-fourths of WP2, roughly parallel to the trailing edge of the dactylopatagium and connecting laterally with the posterolateral part of Fold Line C, and a second that also parallels the trailing edge of the dactylopatagium and connects the anteromedial part of Fold Line C with the posterolateral part of Fold Line D. The presumed courses of Fold Lines C and D that are not visible are indicated in Figure 6.2 by dashed lines. The extraneous folds may have resulted from post-mortem flattening of the patagium onto the planar substrate in the same way that the spanwise undulations occurred at mid-chord in the Zittel wing. Fold Line E extends from the distal third of WP2 to the trailing edge behind the lateral third of WP4, and is folded such that behind the middle of WP4 the trailing edge is not visible and the edge of the fold forms the posterior margin of the wing impression. Note that the folding of the lateral dactylopatagium at Fold Line E suggests that there is another unseen fold between Fold Lines D and E.
Striae and other traces.—Both wings of the Marsh specimen preserve rather smooth surfaces with fine striae that are best viewed under low angle illumination (Fig. 6), and because the right wing preserves an impression of the ventral surface whereas the left preserves an impression of the dorsal surface, striae were present on both surfaces. The left wing exhibits a radiating pattern of shallow linear striae (Fig. 6.1), which although similar to the pattern of the raised longitudinal strips of the Zittel wing are shorter, fewer, and more widely spaced (~8 per 5mm in the medial left dactylopatagium). In addition, the striae are not as regular as the Zittel wing’s raised long- itudinal strips and in the posteromedial part of the impression behind Fold Line B they are often sinuous and some appear to branch. The right wing preserves striae similar to those of the left wing, but there are fewer of them. In addition, an impression of what may be the medialmost parts of the dactylopatagium or the plagiopatagium is present in the area between the left tibia and left foot and extending onto the area of the ribs. The impression consists of what seem to be rather straight striae intersecting one another are roughly right angles to produce a
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