Sinosauropteryx
"Sinosauropteryx" was a small bipedal theropod, noted for its short arms, large first finger (thumbs), and long tail. The taxon includes some of the smallest known adult non-avian theropod specimens, with the holotype specimen measuring only in length, including the tail. However, this individual was relatively young. The longest known specimen reaches up to in length, with an estimated weight of .
Ankylosaurus
"Ankylosaurus" was the largest-known ankylosaurine dinosaur and possibly the largest ankylosaurid. In 2004 the American paleontologist Kenneth Carpenter estimated that the individual with the largest-known skull (specimen CMN 8880), which is long and wide, was about long and had a hip height of about . The smallest-known skull (specimen AMNH 5214) is long and wide, and Carpenter estimated that it measured about long and about tall at the hips. In 2017, based on comparisons with more complete ankylosaurines, the Canadian paleontologists Victoria Arbour and Jordan Mallon estimated a length of for CMN 8880 and for AMNH 5214. Though the latter is the smallest specimen of "Ankylosaurus", its skull is still larger than those of any other ankylosaurins. A few other ankylosaurs reached about in length. Because the vertebrae of AMNH 5214 are not significantly larger than those of other ankylosaurines, Arbour and Mallon considered their upper range estimate of nearly for large "Ankylosaurus" too long, and suggested a length of instead. Arbour and Mallon estimated a weight of for AMNH 5214 and tentatively estimated the weight of CMN 8880 at . Benson and colleagues also estimated the weight for the animal of AMNH 5214 at in 2014.