Incredible Preservation of Skin: The Monsecosuchus depereti is a fascinating extinct crocodile, comparable in size to a domestic cat, that inhabited the tropical wetlands of early Cretaceous Spain. Paleontologists have meticulously reconstructed its scales, sensory organs, and even hypothesized stripes along its tail.
Holotype specimen of Monsecosuchus depereti. Image credit: Castillo-Visa et al., doi: 10.1093/zoolinnean/zlag076.
The fossilized skeleton of Monsecosuchus depereti was excavated in 1902 by engineer and geologist Luis María Vidal from a quarry in the Noguera region of Catalonia, Spain.
This 50 cm long specimen has been preserved in the collection of the Barcelona Museum of Natural Sciences for over a century.
“Crocodilians, including both modern crocodiles and their extinct relatives, boast an extensive fossil record that dates back to the Late Triassic period,” states Dr. Oscar Castillo-Viza from the Miquel Cruzafont Catalan Institute of Paleontology at the Autonomous University of Barcelona.
“However, fossilized soft tissues such as skin and cartilage are exceedingly rare in most clades, aside from notable marine thalamozoans.”
Paleontologists utilized ultraviolet (UV) light to identify and describe various cartilaginous and epidermal tissues. Monsecosuchus depereti stands out as one of the most complete and ancient specimens featuring preserved skin among crocodilians.
“Ultraviolet light reveals details that would otherwise remain concealed within the rock,” explained Dr. Castillo-Visa.
Holotype specimen of Monsecosuchus depereti under UV light. Image credit: Castillo-Visa et al., doi: 10.1093/zoolinnean/zlag076.
The study revealed that the epidermal scales of Monsecosuchus depereti formed discrete patches across its arms, thorax, legs, and tail, with the forelimbs and thorax showing the best-preserved skin.
Researchers also identified potential integumentary sensory organs, suggesting that these features evolved in a limited capacity before becoming widespread in later crocodilians.
These specialized sensory structures—abundant on the faces and bodies of modern crocodiles—are sensitive to pressure and vibrations, aiding these reptiles in locating prey in turbid waters. Their origins appear to be more modest than previously thought.
“In today’s crocodiles, these organs serve as receptors for touch and water pressure changes, and can respond to thermal and chemical stimuli,” the scientists noted.
The presence of preserved cartilage tissue in the thoracic region indicates that Monsecosuchus depereti had adaptations for improved respiratory efficiency.
These bony or cartilaginous projections, found in modern birds, enhance thoracic strength and breathing mechanics.
The existence of crocodiles in this ancient species implies they were more active and aerobically capable than the sluggish image commonly associated with modern crocodiles.
“These features reflect that, despite being a primitive species, it was already well-adapted to a semi-aquatic lifestyle,” remarked Dr. Castillo-Visa.
Monsecosuchus depereti lacked two characteristics typical of contemporary crocodiles: deep caudal “fins” and robust, pointed limb scales.
Consequently, this animal likely had a sleeker silhouette than the Nile crocodile.
The research also uncovered evidence of visually striking markings: a color stripe along the tail.
This alternating pattern of dark and light bands is prevalent in modern crocodiles and various reptilian species, serving purposes of camouflage and species recognition.
The realization that such patterns existed during the age of dinosaurs underscores the conservative nature of evolutionary processes.
“Currently, we can’t specify the exact color of the crocodile’s tail, but we anticipate it was similar to modern species, which exhibit diverse color patterns,” said Dr. Albert Serres, a researcher at the Miquel Crusafont Catalan Institute of Paleontology at the Autonomous University of Barcelona.
The research team’s findings were published in the Zoological Journal of the Linnean Society.
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Oscar Castillo – Visa et al. 2026. Soft tissue preservation in Barremian Monsecosuchus depereti (Neoschiinae: Atoposauridae). Zoological Journal of the Linnean Society 207 (2): zlag076; doi: 10.1093/zoolinnean/zlag076
Source: www.sci.news
