Solnhofen flightless theropods
digital painting 2025
Many people, even experts, still assume that the Solnhofen limestones represent one and the same habitat from the Late Jurassic. In fact, the serial sites along the Bavarian Altmühl Valley conceal several distinct communities as well as temporally/stratigraphically different levels. Only against this background, it is then astonishing what similarities the individual localities have in common. Unfortunately, these are difficult to describe for the only indirectly known island habitats.
Besides the primeval birds – in the end, Archaeopteryx is one of the most common Mesozoic theropods in Europe – the small islands amidst the reef landscape were also home to flightless dinosaurs. So far, three are known, and not just three genera, but in fact only three specimens. All of them were not fully grown at the time of their death and were less than 1 metre long. We have no useful estimate of how large they may have been when fully grown. There is no scientific basis for the assumption of only 2 m, according to which carnivores also react with island dwarfism. For the assumption of 8 m or more, like some of their relatives on the mainland, there was probably a lack of sufficiently large territories and enough large prey. This is because herbivorous dinosaurs or other large herbivores of any kind are apparently absent from the Solnhofen archipelago – another typical characteristic of oceanic islands.
The historically oldest known of the dinosaurs shown here is Compsognathus, the large one in the centre. Its phylogenetic relationship does not imply a greater body size. The hair (functionally it would be fur, evolutionarily it consists of primitive feathers) is proven by Chinese compsognathids from the Lower Cretaceous. And although declared invalid for legal reasons, the whole world knows about this certain Brazilian find, which even preserves elongated shoulder spines. With a small question mark about their position on the body and with a purely hypothetical continuation as arm spines (the latter based on evidence from other theropods), they have been experimentally transferred here. It's funny that nobody has asked about this yet, because it's quite strange.
On the right, this is Sciurumimus, known from a complete skeleton with surrounding feathers. This animal is even more clearly a baby, and the adult megalosauroids from elsewhere are several metres long, even breaking the 10 m mark. Not only does this find provide the most primitive direct evidence of protofeathers among theropods. Sciurumimus also triggered the question of whether large - and if so, how large - predators lived on these Jurassic islands. Without large bone finds, it remains a futile discussion with negative evidence.
Finally, Juravenator, also known with a complete skeleton, plus feather remains and parts of the skin surface. According to the sets of information, it could be described as the most complete theropod find in Europe (according to articulation and appearance, it would be Sciurumimus). The illustration is part of an installation that includes a life-size model of the delicate predator. It was therefore clear that this painting had to reflect the same appearance. Why I don't show Juravenator naked and scaled, as some studies claim to have proven, can be read in a publication on sculpting: