Biotalker Posted July 13 Share Posted July 13 I acquired this cretaceous guitarfish, Rhinobatos whitfieldi from Hgula, Lebanon. Although incomplete, it has exceptional preservation. Below is a picture of the fossil and a second image with angled light, showing the texture of the fossil surface. 2 Link to comment Share on other sites More sharing options...
Biotalker Posted July 13 Author Share Posted July 13 The nice preservation is illustrated by the placoid scales and cartilage in the rostrum and ray edge. 2 Link to comment Share on other sites More sharing options...
Biotalker Posted July 13 Author Share Posted July 13 Since rays are so flat, the fossil presents certain aspects of its anatomy more clearly than other vertebrates. In these images below, you see the viscera divided by the pectoral girdle into anterior and posterior compartments. In general, the anterior region has respiratory, circulatory and central nervous system organs (blue circle) whereas the posterior cavity has digestive, excretory and reproductive organs (red circle). 2 1 Link to comment Share on other sites More sharing options...
Biotalker Posted July 13 Author Share Posted July 13 In the area where the large (and oily) liver would be, just caudal to the pectoral girdle, I see a pink color within the fossil. I have looked at many rhinobatos pictures online and I do see darker coloring very often when that compartment is well preserved. Examination of the pink color reveals red particles within the fossil matrix. Under 95X which is the limit of my scope, these particles can be clearly seen compared with a part of the gut without pigment. 1 Link to comment Share on other sites More sharing options...
Biotalker Posted July 13 Author Share Posted July 13 Removing some fossil matrix from the pigmented and non-pigmented area of the gut area and spreading on a slide suggests the pigment is not just on the surface but also deep. I’m not sure what this observation may mean but given the remarkable preservation of soft tissues in these Lebanese layers, there may be an interesting story here. 1 1 Link to comment Share on other sites More sharing options...
rocket Posted July 13 Share Posted July 13 Sometimes the lebanese fossils do really have an incredible preservation..., thanks for showing your specimen Hard to get better or similar ray or sharks from other sites in the world... When I compare it with Solnhofen-sharks or rays the lebanese mostly have the better preservation 1 Link to comment Share on other sites More sharing options...
ynot Posted July 14 Share Posted July 14 Nice fossil The coloration where the liver was may be caused by a higher concentration of iron in the organ during life. - Just a offhand thought. 1 Link to comment Share on other sites More sharing options...
NickG Posted July 16 Share Posted July 16 Get a UV lamp! Link to comment Share on other sites More sharing options...
Biotalker Posted July 21 Author Share Posted July 21 On 7/13/2024 at 8:08 PM, ynot said: higher concentration of iron in the organ during life. I agree, without further tests, iron is probably the most likely cause for the color. Link to comment Share on other sites More sharing options...
Biotalker Posted July 21 Author Share Posted July 21 On 7/15/2024 at 8:46 PM, NickG said: Get a UV lamp! OK, done! 2 Link to comment Share on other sites More sharing options...
NickG Posted July 21 Share Posted July 21 Nice! Do any more details pop out if you change your lighting angle? Link to comment Share on other sites More sharing options...
Recommended Posts
Create an account or sign in to comment
You need to be a member in order to leave a comment
Create an account
Sign up for a new account in our community. It's easy!
Register a new accountSign in
Already have an account? Sign in here.
Sign In Now