Nope, this is NOT Dilophosaurus


The large double-crested theropod dinosaur displayed at the Museo delle Scienze (MUSE). Surely this is Dilophosaurus right!? Surprise, it's not.

Nope, the mounted skeleton you see in the photo, a cast displayed at the Museo delle Scienze (MUSE), is not actually Dilophosaurus wetherilli. What you're actually seeing here is instead another early theropod dinosaur, the Chinese Sinosaurus triassicus. 
Despite the name, Sinosaurus is from the Early Jurassic, and it's an early example of large theropod dinosaur: it's been recently estimated at around 5-6 m long and more than 800 kg in weight (Liang et al. 2024). Other than S. triassicus, a second species, S. sinensis, is usually ascribed to the genus (see Zhang et al. 2023 and references therein). 

Another view of the same mounted skeleton, from a slightly different angle. Note the somewhat surprisingly thin skull.

As you can see from the photos, Sinosaurus had a relatively delicate skull construction with a pair of fragile crests on the dorsal side of the skull (we'll get to them later), indicating a relatively weak bite, and this, combined with well developed forelimbs, slender body and long legs, suggests that it was a fast hunter of small-to medium-sized prey, using both the mouth and the forelimbs to kill. This may also be corroborated by the surface/volume ratio of its body, which suggests a moderate heat dissipation rate (which tends to slow with increasing body mass) (Liang et al. 2024). 

Speedy Sinosaurus running for it.

The most striking feature of Sinosaurus is its double crests, made from the nasal and lacrimal, which have often drawn comparison with, you guessed it, Dilophosaurus wetherilli: indeed, S. sinensis was originally described as a new species of Dilophosaurus (hence the museum label). However, these similarities seem to be superficial, as Sinosaurus crests differ from those of Dilophosaurus in symmetry and thickness (Zhang et al. 2023 and references therein). 

Closeup of the skull, note the peculiar fenestrations on the crests. 

You can also see on the mount that the crests of S. triassicus feature a series of openings, which at least in one specimen seem to have contributed to a complex pneumatic system (Zhang et al. 2023). Interestingly, S. sinensis lacks these openings, having only shallow fossae instead (Zhang et al. 2023).
It now seems that nasolacrimal crests were a common feature in early theropods, being also plesiomorphically present in many ceratosaurs and tetanurans, and that "Dilophosauridae" may either not be monophyletic (Marsh & Rowe 2020), or not include Sinosaurus anyway (Cau 2024). Regarding the actual phylogenetic affinities of Sinosaurus, these are quite unstable, with different phylogenies finding it in different positions, including outside of Averostra (the clade containing Ceratosauria and Tetanurae), or in a basal position within Ceratosauria or Tetanurae (e.g. Hendrickx and Mateus 2014; Rauhut & Pol 2019; Baiano et al. 2020; Cau 2024). 

A montage of more views of the mounted skeleton, also notice the cool effect with the accompanying artwork that is created when seen from the right angle.

This mount is also interesting because it's potentially chimeric: as Dan Folkes suggested, the pelvis and legs may actually belong to a sauropodomorph (and by the way, go check his blog , where you can also find his skeletal reconstructions of both S. triassicus and S. sinensis).

References 
  • Liang, Q., Falkingham, P., L., & Xing, L. (2024). Virtual skeleton and body mass for revealing the life strategies of Sinosaurus, Historical Biology, DOI: 10.1080/08912963.2024.2385615
  • Zhang ZC., Wang T., You HL. (2023). A New Specimen of Sinosaurus triassicus (Dinosauria: Theropoda) from the Early Jurassic of Lufeng, Yunnan, China. Historical Biol. 36(4):1–15. doi: 10.1080/08912963.2023.2190760.
  • Marsh A.D., Rowe T.B. (2020). A comprehensive anatomical and phylogenetic evaluation of Dilophosaurus wetherilli (Dinosauria, Theropoda) with descriptions of new specimens from the Kayenta Formation of northern Arizona. Journal of Paleontology. 2020;94(S78):1-103. doi:10.1017/jpa.2020.14
  • Cau A. (2024). A Unified Framework for Predatory Dinosaur Macroevolution. Bollettino della Società Paleontologica Italiana, 63(1): 1-19. doi:10.4435/BSPI.2024.08
  • Hendrickx, C., and Mateus, O. (2014). Torvosaurus gurneyi n. sp., the largest terrestrial predator from Europe, and a proposed terminology of the maxilla anatomy in nonavian theropods. PLOS One, v. 9, p. 388905.
  • Rauhut, O.M., Pol, D. (2019). Probable basal allosauroid from the early Middle Jurassic Cañadón Asfalto Formation of Argentina highlights phylogenetic uncertainty in tetanuran theropod dinosaurs. Scientific Reports 9 (1):18826. doi:10.1038/s41598-019-53672-7
  • Baiano, M.A., Coria, R.A. and Cau, A. (2020). A new abelisauroid (Dinosauria: Theropoda) from the Huincul Formation (lower Upper Cretaceous, Neuquen Basin) of Patagonia, Argentina. Cretac. Res. 110, 104408.

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