The Best-Preserved Dinosaur

Its 2025. I’m approaching the end of my palaeontology studies, and it concludes with a journey across southern Germany. This trip saw me and my classmates visit many of the country’s natural history museums. The first museum we visited was the Naturmuseum Senckenberg in Frankfurt. It was a wonderful museum that I sadly didn’t have time to fully explore and hope to return to one day.

Although there are several choices in where to go upon entering the museum, the dinosaur footprints on the floor guide you down the centre staircase. As I made my way down the stairs, I found myself in a large, spacious hall full of giant dinosaurs. T. rex, Triceratops, Stegosaurus, giant pterosaurs hanging from the ceiling and many others. With all these amazing displays, its easy to overlook a much smaller, but all the more spectacular specimen.

Off to the side is a small, narrow cabinet containing an incredible fossil of a Psittacosaurus (si-tak-o-sore-us). What makes the specimen so special is how well-preserved it is. Not only does it include the skeleton, but also softer parts of the body that very rarely fossilise. While I was well aware of the fossil’s existence, I didn’t know this was the museum that housed it. When I saw it, I was very excited.

Figure 1: SMF R 4970 in the Naturmeuseum Senckenberg, 2025.

The fossil is believed to have been illegally exported from China to Arizona and subsequently taken to multiple countries in Europe via the fossil black market before it was purchased by the museum in 2001 and designated as SMF R 4970. It is thought to have been excavated from the Yixian (yee-shan) Formation in Liaoning Province, China. This formation is part of a larger series of rocks called the Jehol Group. It is famous for its incredible diversity and exquisite preservation resulting from high volcanic activity at the time.

Meaning “Parrot Lizard” due to its skull resembling that of a parrot (scientifically called Psittacoformes), Psittacosaurus is an early member of a group of plant-eating dinosaurs called ceratopsians, making it an older and primitive relative of Triceratops. Unlike its famous cousin, Psittacosaurus was small, walked on two legs instead of four, the frill on the back of the head was little more than a ridge and most species didn’t have those characteristic facial horns. It did however have horns projecting from its “cheeks,” a common trait among ceratopsians.

Psittacosaurus lived during the Early Cretaceous period between 130-100 million years ago in Central and Far East Asia. It is known from hundreds of specimens, some of which are very well preserved. These include individuals of all ages from hatchling to adults. Unsurprisingly, it can be regarded as the best-known non-bird dinosaur to science. It is also the most species rich genus of non-bird dinosaur with around 9-13 known species. By comparison, Triceratops only has two species and most dinosaurs have only one. Surprisingly, despite the preservation, this SMF R 4970 has not been assigned to any particular species.

Preserved skin on SMF R 4970 show differently sized and shaped scales around the body. They also show that this Psittacosaurus was counter-shaded with darker brown colouring on the top and lighter colouring underneath. This colouration is common among forest animals where Psittacosaurus is believed to have lived. Large scales on the shoulders appear as dark spots that may have broken the body outline. The face was dark, perhaps used for display purposes.

Bristles run along the top of the tail. It’s not yet known what exactly these are. Many dinosaurs had feathers, but they are not known in ceratopsians. Whether these bristles are homologous with feather is unclear.

Most remarkable of all, are the presence of the belly button and the cloaca (an opening in amphibians, reptiles and birds that contains the naughty bits). These are the first and oldest known examples of these features. The area around the cloaca is dark, like the face, and so may have been used for display like the backside of a baboon. Just next to the cloaca is a white coprolite – fossil poo – still inside the animal.

With this remarkable preservation, palaeoartists have been able to give very accurate and detailed – sometimes too detailed – reconstructions. Just next to the specimen, the museum has a life-size recreation of the animal. I don’t know how old this model is but it lacks a few features like the dark face. Nonetheless, it looks phenomenal. It goes to show how much we still have to learn about dinosaurs.

Figure 2: The museum’s slightly outdated, but still beautiful, reconstruction of Psittacosaurus.

Figure 3: A 2016 reconstruction of SMF R 4970 by Palaeontologist and artist Bob Nicholls.

Jack Lawes is currently a student on the MA Museum Studies program at the University of Leicester.