Florida Bone scrap taphonomy

[Plantguy]

Hi Bone Gang,

So awhile back someone posted a picture of an unknown that looked similar to alot of bone pieces I have and that made me go back and take a look at a bunch of them even closer and a couple questions arose about one particular bone scrap. 

 

I was looking around for answers about it and ran into this recent book title and am considering getting it...may check it out thru one of the libraries....looks fascinating..

1) Does anyone happen to have it/have used it and would recommend it?

Atlas of Taphonomic Identifications: 1001+ Images of Fossil and Recent Mammal Bone Modification (Vertebrate Paleobiology and Paleoanthropology) 1st ed. 2016 Edition

by Yolanda Fernandez-Jalvo (Author), Peter Andrews (Author)

 

 

So here's a quick pic of some of the types of plain old fairly small chunks of bone that are fairly common from around here in central Florida--Miocene/Pliocene/Pleistocene in age. The Florida folks see em quite a bit.

Most are very dense and darker in color from our creeks/rivers ranging from brown/black to a creamy white at rarer inland locales and are heavily mineralized. Some show minor porosity and some have very distinctive longitudinal cracking and others very polished and smooth. Many are dugong rib fragments, probably at least the left 2 in this picture above and some may be from other land critters and be other skeletal parts. Occasionally you see bite marks and borings.

 

There are other hunting areas where the bone fragment finds are more exclusively marine and its common to find other thinner flatter fragments that have more and wider areas of porous bone on the interiors, probably whale or other marine mammals. Here are 2 specimens showing their exterior weathering:

 

Some longitudinal cracks and and an irregular rippling/undulating/uneven surface 

 

Some longitudinal cracks and exfoliation..

 

Here's the one specimen below that I am particularly curious about and looking for your thoughts as it exhibits a number of different features all on the same bone. Seems to pretty water worn and smooth overall, exfoliating a bit but does show some internal details in various places.  Thinking it might be a dugong fragment although it doesnt show any characteristic banding in the end view and in one area seems very spongy/porous. 

Couple of general views showing the longitudinal grooves.

 

A closeup of the dendritic like grooves/structures---maybe the vascular system between the pores? You can see some minor cracks/exfoliation also occuring in spots in the top and lower left..

 

A 2nd closeup showing a couple of grooves that seem to loop and overlap?

 

Top back edge views showing a rounded now polished cancellous area. 

 

A  back view showing a .5cm outer layer that has been broken away showing some internal porosity. 

 

An end view showing that  same porosity. 

 

 

2) I'm mostly wondering about the longitudinal grooves/lines and whether they are simply water worn/weathering of cracks in the bones or perhaps a polishing of the internal vascular bone feature, some bioerosion activity or maybe both or something else? 

 

3) What do you think about those little grooves with the possible loop or two? Bioerosion?  

 

Welcome all explanations/ideas...maybe some simple weathering that I'm just trying to make more complex and am wondering about out loud! 

Thanks!

 

Regards, Chris 

 

 

[Plantguy]

@Harry Pristis

Hi Harry, curious as to what kind of expertise you have in bone taphonomy/weathering? Guessing you've seen your fair share of things. Do you have any weathered examples similar to the one above and can identify what the causes/grooved textures are?  Thanks. 

Regards, Chris 

[Harry Pristis]

 

Chris, all is see on the bone is a mix of natural crazing and shark tooth scrapes.  But, that's just my impression.

 

 

[Plantguy]

19 hours ago, Harry Pristis said:

 

Chris, all is see on the bone is a mix of natural crazing and shark tooth scrapes.  But, that's just my impression.

 

 

Thanks Harry appreciate the feedback and looks! It doesnt take much to make me stop, wonder and ask a question or two or three....

Regards, Chris