Best-preserved armoured dinosaur

The best-preserved armoured dinosaur (and some would argue the best-preserved dinosaur overall) is the specimen TMP 2011.033.0001, known as the "Suncor nodosaur". The holotype of Borealopelta markmitchelli (a relative of the more famous Ankylosaurus), it was unearthed from the Clearwater Formation of northern Alberta, Canada, dating back c. 110 million years to the Early Cretaceous. When alive, it is estimated to have been 5.5 m (18 ft) long and to have exceeded 1,300 kg (2.860 lb). Only the front of the specimen is preserved, so it is not the most complete dinosaur fossil, but it can be regarded as the best preserved based on several criteria. Firstly, the entirety of the specimen is covered in preserved soft tissue in the form of skin and keratinous scales, as well as evidence of its colour (reddish-brown). Secondly, the specimen retains the original three-dimensional shape of the animal as it was in life, and thirdly, the dinosaur still retains stomach contents, indicating its last meal. The palaeontologically significant specimen is housed at the Royal Tyrrell Museum in Drumheller, Alberta, Canada, and is currently on public display.

The specimen was discovered incidentally by Sean Funk during mining operations at an oil sands mine (Suncor Millennium Mine) on 21 March 2011, and collected by crews from the Royal Tyrrell Museum in the following weeks. The specimen took five-and-a-half years to prepare by technician Mark Mitchell and the species was named in his honour in 2017.

A 2020 study into the Suncor nodosaur's stomach contents indicates its herbivorous diet comprised leaves, ferns, cycads and conifers, among other plants. It also contained stones, which scientists suggest it swallowed to help break down its food.