Nanotyrannus lancensis

Nanotyrannus lancensis or "tiny tyrant" is a tyrannosaurid dinosaur from the late Cretaceous period believed to reach ~20 feet. There is much discussion regarding the Nanotyrannus being a juvenile or young T. rex, but there are many arguments in favor of the separate species including tooth count, fused cheek bones, proportionally larger hands, etc. Fossil remains include well preserved teeth, bones, and claws, and are highly valued by collectors. These top quality specimens were all legally collected from private ranch land with the owners permission in the northwestern US (Montana). All teeth are late Cretaceous, Hell Creek Fm., 67 MYA.

Note - Nanotyrannus is a controversial species. Many paleontologists consider these teeth are from young Tyrannosaurus rex. 

Note - we measure all of our teeth "straight line".