A Little* Something I've Been Workin' On!

[kauffy]

I thought i would share with you one of my most recent projects, it's been on standstill for a couple of months due to school but im hoping to finish it up in the next week or so. Basically i have been putting together a shattered Rabbit maxilliary, and when i say shattered i mean its in many many pieces! (you can see some obvious breaks but a lot of the flat surfaces you see are actually many bits put together) What you see is what i have put together thus far, unfortunatley many of the tiny splinters that make up the rest of it are proving extreamly difficult to find in the rest of the bone 'stew'. The main parts im trying to find and put together are the ends of both tooth rows which connect the outer part of the skull to the palate, until then im not going to start placing the teeth back in.

I also found a lot of other bones, many of which are rabbit and some which are most probably rabbit. There was an unusual concentration of larger bones in this block of sediment. Whether or not these bones are from the same individual i cannot tell, but an interesting association. (although some probably are from other critters!)

I shall keep you all updated if when i finish it off, until then, enjoy the pics!

Some of associated bones include:

-3 lower jaw teeth and two lower jaw fragments

-Two (left and right/ hind and forelimb) Calcaneums

-Femur fragment

-humerus Fragment

-Other long bones, as yet un-identified...some very well could be rabbit

oh and for those of you who dont know: Late Pleistocene (Rancholabrean) Fissure fill in Eocene ogala limestone, Marion Co. FL. Raptor pellet accumulation!

Oh also, i apologize the pictures are not very good, the camera i was using has a crud macro setting, so i tried the scanner but it only works on flat objects, so most of the pics are quite bad quality.

[kauffy]

the other pics:

[Auspex]

The pics are good enough to show (I think) signs of acid etching on these meal remnants.

Very cool!

[kauffy]

The pics are good enough to show (I think) signs of acid etching on these meal remnants.

Very cool!

I was trying to figure out why some of the bones are very worn (calcaneums are an example) and it did not occur to me until now that it may very well be to do with digestive processes.... i really dont know too much about raptor pellets, but please Mr Auspex, can you elaborate the possibility of 'acid etching' on some of the bones? Have you seen anything similar in modern pellets?

One thing can be sure about these predators; they did a darn good job of chomping everything up!

Oh and Auspex (im struggling with the camera) but im trying to get a picture of that other bird beak fragment i found...it will be up asap

[Auspex]

...can you elaborate the possibility of 'acid etching' on some of the bones? Have you seen anything similar in modern pellets?

One thing can be sure about these predators; they did a darn good job of chomping everything up!

The breakage and the etching both argue for hawk or eagle ingestion. Owls swallow more stuff whole and their digestive acid is weak (the subsequent pellets often represent a single meal, with the dis articulated skeleton being in good shape). Hawks are capable of digesting more of the "tough stuff" and will dismember their prey more thoroughly; especially when feeding young in the nest. The "roost" in this case may have been a well established nest site.

[kauffy]

The breakage and the etching both argue for hawk or eagle ingestion. Owls swallow more stuff whole and their digestive acid is weak (the subsequent pellets often represent a single meal, with the dis articulated skeleton being in good shape). Hawks are capable of digesting more of the "tough stuff" and will dismember their prey more thoroughly; especially when feeding young in the nest. The "roost" in this case may have been a well established nest site.

Makes sense, thankyou for that elaboration! Im curious though, this site seems to represent a huge variation in prey items, snakes, birds, lizards, turtles, mammals...are hawks opertunistic, or do they target more specific prey? Owls, i would have thought to be a likely candidate for a wide variety of different prey items?

Help me master, i am confused! Really, just trying to figure out what bird is most likely to leave pellets like these!

"The "roost" in this case may have been a well established nest site." < im sure it was, probably generations of birds roosted there to leave such extensive amounts of bone!

EDIT: i seem to answer my own questions, here is some info on the site i got a little while ago from Richard Hulbert. MORGAN AND HULBERT CENOZOIC FOSSILS IN FLORIDA PALEOKARST

The Reddick 1 fauna was collected from an abandoned limerock quarry near Reddick in Marion County (Figure 3.22). The fossils were derived from sediment-filled caverns/solution pipes in the Ocala Limestone. It is difficult to determine the original size and shape of the karst features because the limestone in which the clays and sands were deposited has been entirely mined away. There are four sublocalities within the Reddick 1 quarry, Reddick 1A-D. Reddick 1A, the so-called “Rodent Beds,” consists of a layer 1 m thick, 3 m wide, and extends for a distance of 55 m (Brodkorb, 1957). Gut and Ray (1963) thought Reddick 1A was an owl pellet accumulation in a cave. The similarity in fauna, age, and lithology suggests the four Reddick localities may have been part of a single large cave system that became completely filled with sediments. Reddick has one of the most abundant and diverse vertebrate faunas of any Rancholabrean site in Florida, with at least 161 species: nine amphibians, 32 reptiles, 64 birds, and 56 mammals (Brodkorb, 1957; Auffenberg, 1963; Gut and Ray, 1963; Webb and Wilkins, 1984). In discussing the Reddick fauna, Brodkorb (1957, p. 130) stated that “The abundance of bones of small vertebrates at this site is almost beyond comprehension. Remains of small rodents, insectivores, and bats are especially common.” Although small terrestrial vertebrates dominate the fauna, more than 20 species of large mammals are present and there are also a few freshwater taxa of amphibians, reptiles, and birds. The presence of seven species of bats, with the large vampire Desmodus stockii especially abundant (over 300 elements from Reddick 1B and 1C), as well as the overall similarity of the Reddick 1A Rodent Beds to an owl pellet deposit, strongly suggest that Reddick represents a former cave system (Gut and Ray, 1963; Morgan, 1991).

[Auspex]

IMHO, there is too much breakage and too much etching for these to have been from owl pellets.

I'm thinking large Buteos are responsible for much of the remains.

[Terry Dactyll]

You learn something every day.... and do keep us updated with you assemblage...

[Shamalama]

Very interesting. I love learning about a sites paleobiology and in turn how it's stratigraphy is related.

[kauffy]

IMHO, there is too much breakage and too much etching for these to have been from owl pellets.

I'm thinking large Buteos are responsible for much of the remains.

Buzzards ey, interesting... i would have to agree with you after googleing images of owl pellets, all the debris seem to be very intact.

But* i think we are not taking the deposition of the bones into account. The site is not a cave deposit, thus we are not finding the pellets 'in-situ'. The bones and sediment would have had to been washed into the solution pipes and fissures, this may have resulted in damage to the bones to a great extent?

Also, ive noticed that the bones in situ are broken, (that is in the 'dirt' sediment) kind of hard to explain but a complete bone in the dirt, fractured in 4-5 places, and once washed from the sediment it is not complete but becomes a bunch of fragments. So im thinking that depositional forces that have acted on the sediment over time may also contribute to the damage on all these bones.

All of the damage we are seeing may not in fact be from the birds which preyed on them...

[Auspex]

All of the damage we are seeing may not in fact be from the birds which preyed on them...

Aye, there's the rub.

How to interpret the condition of a bone that has been subjected to meteorologic, geologic, and human (the matrix was collected, washed, and screened, no?) forces? I think a trip down taphonomy road might add understanding. How far down that road you go depends on whether you are more interested in understanding the rabbit, his habitat, or how his bits and pieces got to your work bench.

I love fossils...

[mommabetts]

Interesting thread.

[kauffy]

Aye, there's the rub.

How to interpret the condition of a bone that has been subjected to meteorologic, geologic, and human (the matrix was collected, washed, and screened, no?) forces? I think a trip down taphonomy road might add understanding. How far down that road you go depends on whether you are more interested in understanding the rabbit, his habitat, or how his bits and pieces got to your work bench.

I love fossils...

How about both roads!? and lets go down as far as we can! hah! thats what i love, the knowledge i can gain from these fossils. I think in order to truly appreciate something you have to respect every aspect of its existence. (<deep i know: how about philosopher as a profession when i leave school?) But i was seriously thinking about this the other day, how each bone amongst thousands of others, representing many individuals not only survived for thousands of years, but only by sheer luck were the spared by the construction of the mine where they rested. Makes me think of that statistic, i cant remember but it was some tiny percentage taking into account the likely-hood of something fossilizing, preserved for thousands/millions of years, then being exposed to the elements, and being found before it was turned back into sediment.

Im getting off track here now arnt I! i tell you what though, i couldnt think of a more interesting deposit of bones than raptor pellets...it just strikes something within me, paleoecology is awesome! ( i guess it takes my passion for birds, fossils, 'micro' fossils, and animals in general!)

Side note: We shall be in mourning for 3 days as the light hanging over my desk fell today, crunching a near perfect skunk jaw, like humpty, all of the kings horses and men couldnt put it back together again It also knocked off a jar full of teenie tiny bat bones off my desk onto the floor..which i found to be a lot of fun picking up!

I did learn though, if a light must be used, do not counterweight it with a marble trophy...this just adds to the 'crunching effect' when it falls....

PHEW sleep time, pictures of the rabbit maxillary put together tomorrow!

[Auspex]

But i was seriously thinking about this the other day, how each bone amongst thousands of others, representing many individuals not only survived for thousands of years, but only by sheer luck were the spared by the construction of the mine where they rested.

If you want to feed your philosophical hunger with a huge dose of universal perspective, read Bill Bryson's "A Short History of Nearly Everything". I dare you to try and put it down!

[Harry Pristis]

Makes sense, thankyou for that elaboration! Im curious though, this site seems to represent a huge variation in prey items, snakes, birds, lizards, turtles, mammals...are hawks opertunistic, or do they target more specific prey? Owls, i would have thought to be a likely candidate for a wide variety of different prey items?

Help me master, i am confused! Really, just trying to figure out what bird is most likely to leave pellets like these!

"The "roost" in this case may have been a well established nest site." < im sure it was, probably generations of birds roosted there to leave such extensive amounts of bone!

EDIT: i seem to answer my own questions, here is some info on the site i got a little while ago from Richard Hulbert. MORGAN AND HULBERT CENOZOIC FOSSILS IN FLORIDA PALEOKARST

The Reddick 1 fauna was collected from an abandoned limerock quarry near Reddick in Marion County (Figure 3.22). The fossils were derived from sediment-filled caverns/solution pipes in the Ocala Limestone. It is difficult to determine the original size and shape of the karst features because the limestone in which the clays and sands were deposited has been entirely mined away. There are four sublocalities within the Reddick 1 quarry, Reddick 1A-D. Reddick 1A, the so-called “Rodent Beds,” consists of a layer 1 m thick, 3 m wide, and extends for a distance of 55 m (Brodkorb, 1957). Gut and Ray (1963) thought Reddick 1A was an owl pellet accumulation in a cave. The similarity in fauna, age, and lithology suggests the four Reddick localities may have been part of a single large cave system that became completely filled with sediments. Reddick has one of the most abundant and diverse vertebrate faunas of any Rancholabrean site in Florida, with at least 161 species: nine amphibians, 32 reptiles, 64 birds, and 56 mammals (Brodkorb, 1957; Auffenberg, 1963; Gut and Ray, 1963; Webb and Wilkins, 1984). In discussing the Reddick fauna, Brodkorb (1957, p. 130) stated that “The abundance of bones of small vertebrates at this site is almost beyond comprehension. Remains of small rodents, insectivores, and bats are especially common.” Although small terrestrial vertebrates dominate the fauna, more than 20 species of large mammals are present and there are also a few freshwater taxa of amphibians, reptiles, and birds. The presence of seven species of bats, with the large vampire Desmodus stockii especially abundant (over 300 elements from Reddick 1B and 1C), as well as the overall similarity of the Reddick 1A Rodent Beds to an owl pellet deposit, strongly suggest that Reddick represents a former cave system (Gut and Ray, 1963; Morgan, 1991).

You seem to have done an outstanding bit of research, 'Kauffy'. I can confirm that Gary Morgan (author cited above) thought that these bones were from an owl (generations of owls) roosting in a cave. Remember that owls are nocturnal or crepuscular hunters which would be the time to catch skunks and many other small vertebrates in Florida.

Surface run-off would have carried the bones to their final resting place in a channel (solution pipe) some twenty or thirty feet below the modern surface. This water transport scattered and etched the bone to some degree beyond the digestion by an owl.

It is a similar explanation to that posited for the Reddick site. WTG!