what is this my dog found it in our backyard in South Florida. We live on a salt water canal if that helps…
It looks like a tooth, and a big one, if that helps. A molar from some sort of grazer.
The molars of a herbivore, maybe a young cow, deer or small horse. If I had to guess, it would be a horse. The wear is so level, it is probably the result of human intervention. (having the sharp points filed down periodically is a normal part of horse care).
I’m just a landlubber from Illinois, but I’ve been to Florida a few times. I was thinking that it looks like some kind of coral. Organ pipe coral or some such that has tubes side by side. I know coral loses its vibrant colors and fades to gray after it dies.
It’s some kind of coral.
Not an herbivorous jaw bone. Not much of that in that part of S. FL. Maybe if the OP lives near Lake Okeechobee, but she/he said South Florida. That means West Palm-Ft. Lauderdale-Miami.
Here’s a tube coral. Scroll down to the very bottom. The bit your dog found looks like it could be a dried out piece that got broken off. Shells and coral wash ashore and find their way into the canals that connect to the ocean.
It’s some old guy’s partial plate. Lots of retirees in South Florida.
Is it fossilized? Looks similar to a portion of a mastodon molar.
[/QUOTE]
Since the University of South Florida is in Tampa, I think you’re being overly restrictive on what constitutes south Florida.
I don’t know if it’s a piece of coral or a tooth, but there are plenty of cattle and horses in south Florida.
Definitely not a mammalian tooth. It lacks roots, and the pattern of the “cusps” is unlike any extant mammal, including deer, cow, horse, or manatee (although there is a vague resemblance to an elephant tooth).
It’s probably some kind of marine organism; tube coral is a possibility.
There’s a vague resemblance, but that’s not it. Nor mammoth.
Yeah, except look at a map. Tampa is in Central Florida. I can’t help it the school is mis-named.
I’ve lived in Florida for nearly 20 years, four of that in South Florida. Don’t tell me what we call our regions down here and I won’t tell you what word we northern Ohioans used for people who lived south of I-70.
Sorry south florida is too vague, I live in Ft Lauderdale…
thank you for everyones thoughts! i have no idea where my dog found it in our yard. he just dropped it by the front door…
If the word ain’t hillbillies, you’re in for a fight. 
My wife graduated from USF; I was shocked when I found out it was in Tampa.
I consider everything below the trail starting in Naples to be south Florida, but I’m just a hillbilly.
Typically, if you are referring to anything south of Lake Okeechobee and you are including the west coast, then you are referring to “Southern Florida.” The term “South Florida” is generally meant to refer to everything from about West Palm to Miami, sometimes the Keys are included in that, but culturally, the Keys are a little different, so they usually don’t really count when people are talking about South Florida. "Central Florida refers to what is also known as the I-4 Corridor, which is Tampa/St. Pete, Orlando, and Daytona. “North Florida” refers to anything north of Ocala, but not necessarily the panhandle. Jacksonville is North Florida but Pensacola is the Panhandle.
I don’t know why USF called itself that. Probably because UCF was taken. Does anyone know which came first?
:: shrugs ::
Oh, and ETA: I stand my by coral assessment. It’s a bit of coral the dog dragged in. It happens. I find stuff like that all the time and I live 30 miles inland.
Is it dense like bone? It almost looks to me like a piece of a wasps nest.
Archaological horse teeth. the folded surface can be seen in some of the teeth in the top left corner.
Horse Molars for sale (who knew?)
Scroll down on the left to see fossil horse molars found in Florida
extending the hijack…
University of West Florida was already taken by a school in Pensacola and University of West Peninsular Florida doesn’t exactly roll off the tongue. 
It’s not teeth, no grazer has 3 rows of teeth as shown in picture 1. I’m guessing coral but I am unsure. But it is most definately not teeth, though it does somewhat look like it could be teeth in the other 2 photo’s it’s not teeth. That’s all I got, I hope you can figure it out good luck.
My first thought was fossilized pack of cigarettes, LOL! It looks just like a pack of filters from the brand my Grandmother used to smoke. they had a thin plastic ring around each filter, and a hole down the middle just like that.
Weird, the things you remember after thirty-odd years!
Chupacabra, obviously.
It doesn’t look like any horse teeth I’ve ever seen. I’m betting on the coral theory.