How To Identify Your Finds (Part 10 of 10)
10) Identifying the Odds and Ends If you've been following my advice so far, you may have a few mystery bits and pieces left over after identifying everything else. Here are some of the more common possibilities: a) Turtle Carapace Some of these may be turtle shell/carapace (See figure 1 below). These are rather boring, flat, grey, slate-like lumps. The thing is you don't normally get slate in Beltinge. Also, when you look at a cross-section of one of these fragments (See bottom image of figure 1), you'll see a characteristic honey-comb texture. b) Fish Vertebrae These are disc shaped objects with concave top and bottom surfaces (Figure 2 below). The sides of the discs (top image of figure 2) often have vertical slots where the 'processes' (supporting structures) would have been. Shark verts are circular when viewed from above (see figure 2, bottom 2 images, and fig 7), have a shallow concave top & bottom, and often have the sort of ridges round the rim you see in the top image of figure 2, also figure 6. They don't have 'processes'. Ray verts are oval when view from above and have a shallow, concave top & bottom (See figs 8 & 9). Bony fish verts are roughly circular when viewed from above with side processes (See figure 5). They have a deep, conical depression in the top & bottom. They are often slightly hour-glass shaped when viewed from the side. c) Bony Fish teeth Bony fish (i.e. Fish with bony skeletons) have teeth that can easily be mistaken for the broken tips off shark teeth. The way to tell them apart is that bony fish teeth have rounded crowns (See figure 3) whilst the crowns of shark teeth have a flattened labial side, usually with a distinct cutting edge. Note: The circular fossil on the right of figure 3 is probably from Abula oweni. They have crushing palettes made up of many of small, cylinder like 'teeth' with dimples in their crowns - See here. Figure 10 is a single 'tooth' from a Phyllodus toliapicus crushing pallet. The crushing surface is smooth and convex, whilst the sides look like a stack of pancakes. The underside is concave. |
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