Early Permian Tridentinosaurus ‘finally reveals its true identity’ – not yet

The headline above attended recent publicity
announcing a new paper by Rossi et al 2024.

According to Michelle Starr, writing for Nature Science Alert
“In the 90-odd years since it was discovered, we’ve never found anything like an ancient, early Permian fossil discovered in the Italian Alps.”

The ‘early Permian fossil’ is Tridentinosaurus antiquus
(Dal Piaz Gb 1932. Lesonardi 1959, Fig 1).

Of course, be wary whenever anyone says, “we’ve never found anything like…”. This should be consider this puffery and hyperbole — because every taxon is related, more or less, to every other taxonl. We all learned this in middle school.

Figure 1. Tridentinosaurus from Rossi et al 2024. ” data-image-caption=”

Figure 1. Tridentinosaurus from Rossi et al 2024.

” data-medium-file=”https://pterosaurheresies.files.wordpress.com/2024/02/tridentinosaurus2024-588.gif?w=170″ data-large-file=”https://pterosaurheresies.files.wordpress.com/2024/02/tridentinosaurus2024-588.gif?w=581″ class=”size-full wp-image-84346″ src=”https://pterosaurheresies.files.wordpress.com/2024/02/tridentinosaurus2024-588.gif” alt=”Figure 1. Tridentinosaurus from Rossi et al 2024. ” width=”584″ height=”1030″ srcset=”https://pterosaurheresies.files.wordpress.com/2024/02/tridentinosaurus2024-588.gif?w=584&h=1030 584w, https://pterosaurheresies.files.wordpress.com/2024/02/tridentinosaurus2024-588.gif?w=85&h=150 85w, https://pterosaurheresies.files.wordpress.com/2024/02/tridentinosaurus2024-588.gif?w=170&h=300 170w, https://pterosaurheresies.files.wordpress.com/2024/02/tridentinosaurus2024-588.gif 588w” sizes=”(max-width: 584px) 100vw, 584px” />

Figure 1. Tridentinosaurus from Rossi et al 2024. Rossi et al reported, “The variation in topography within the specimen is explained as the result of extensive mechanical preparation, possibly aimed at exposing more of the skeleton, although without much success.” and “Coatings such as lacquers, varnishes, and glues, as well as certain artificial pigments are fluorescent under UV light.”

Rossi et al 2024 reported,
“The preservation and appearance of the fossil have puzzled palaeontologists for
decades and its taphonomy and phylogenetic position have remained unresolved. The results reveal… that the material forming the body outline is not fossilized soft tissues but a manufactured pigment indicating that the body outline is a forgery. Our discovery poses new questions about the validity of this enigmatic taxon.”

The 2024 paper repeats findings from the Rossi et al 2021 abstract. If you don’t know by now, this is how paleontology works. Abstracts get published within a year. Papers can take years to get published.

Three years ago Rossi et al 2021 reported,
“We suggest that the body outline and the abdomen have been covered with a layer of black paint (e.g., Bone Black) perhaps to consolidate/protect the specimen. Our findings indicate the absence of soft tissues preserved in T. antiquus but the discovery of small rhomboidal osteoderms uncovers a new biological character that will support future phylogenetic studies of this ancient tetrapod.”

Five years earlier than that (= 8 years ago) the large reptile tree (LRT, 2312 taxa) nested Tridentinosaurus at the base of the Lepidosauriformes largely based on overall proportions plus manus and pes details.

It’s worth remembering that some fossils, like Cosesaurus, are preserved as molds, that can be incredibly detailed negative impressions in the matrix. All the bone and skin are gone, leaving shapes alone, best viewed under low lighting angles to bring out the relief.

Rossi et al 2024 reported,
“T. antiquus has never been analysed in detail using modern analytical techniques, and its taphonomy and phylogenetic position are unknown.”

Not true. The 2016 LRT analysis nested Tridentinosaurus with coeval arboreal ‘rib’ gliders and early lepidosauriformes (Fig 2).

Rossi et al 2024 reported,
“Our results therefore indicate that the purported fossilized soft tissues of T. antiquus are not original but are the result of forgery.”

Figure 1. Taxa at the base of the Lepidosauria include Paliguana, Tridentinosaurus, Lanthanolania, Lacertulus, Gephyrosaurus, Megachirella, Lacertulus and Palaegama. ” data-image-caption=”

Figure 1. Taxa at the base of the Lepidosauria include Paliguana, Tridentinosaurus, Lanthanolania, Lacertulus, Gephyrosaurus, Megachirella, Lacertulus and Palaegama.

” data-medium-file=”https://pterosaurheresies.files.wordpress.com/2020/10/basal_lepidosaurs588.jpg?w=102″ data-large-file=”https://pterosaurheresies.files.wordpress.com/2020/10/basal_lepidosaurs588.jpg?w=347″ class=”size-full wp-image-50425″ src=”https://pterosaurheresies.files.wordpress.com/2020/10/basal_lepidosaurs588.jpg” alt=”Figure 1. Taxa at the base of the Lepidosauria include Paliguana, Tridentinosaurus, Lanthanolania, Lacertulus, Gephyrosaurus, Megachirella, Lacertulus and Palaegama.” width=”584″ height=”1721″ srcset=”https://pterosaurheresies.files.wordpress.com/2020/10/basal_lepidosaurs588.jpg?w=584&h=1721 584w, https://pterosaurheresies.files.wordpress.com/2020/10/basal_lepidosaurs588.jpg?w=51&h=150 51w, https://pterosaurheresies.files.wordpress.com/2020/10/basal_lepidosaurs588.jpg?w=102&h=300 102w, https://pterosaurheresies.files.wordpress.com/2020/10/basal_lepidosaurs588.jpg 588w” sizes=”(max-width: 584px) 100vw, 584px” />

Figure 2. Taxa at the base of the Lepidosauria include Paliguana, Tridentinosaurus, Lanthanolania, Lacertulus, Gephyrosaurus, Megachirella, Lacertulus and Palaegama.

Bottom line:
“Our findings cast doubt on the validity of the taxon. The establishment of the taxon was based on morphological data derived from the observation of the body proportion and measurements of limbs, neck and abdomen (Leonardi 1959). Poorly preserved bones are visible in the hind limbs, but these lack all diagnostic features (e.g. processes, foramens) that are usually used to classify a taxon. Skeletal elements of the forelimbs and autopodia (i.e. hands and feet) and girdles are not visible and the overall shapes of these are evident due to the black paint and thus cannot be considered as characters. The same is true for the abdominal region. Vertebrae are not recognizable in the neck and along the tail. Skeletal elements of the skull are absent, and no bone cross-sections are identified along the fracture where the head of the specimen is supposed to be located. These observations question the actual completeness of the skeleton of T. antiquus. Based on our results only the proportions of the poorly preserved femurs and tibiae/fibulae can be used in comparative phylogenetic analysis.”

As Joe E Brown said at the end of ‘Some Like It Hot’ (the 1959 movie),
“well, nobody’s perfect.”
Again, Tridentinosaurus may represent a mold fossil, preserving skin impressions better than bone.

Rossi et al 2024 concluded,
“The putative soft tissues of T. antiquus, one of the oldest known reptiles from the
Alps, are fake and thus this specimen is not an exceptionally preserved fossil.”

Glean what you can from the fossil, even if it is disappointing or bland.

Rossi et al 2024 also reported,
“Small rhomboidal scales (max. 2 × 0.9 mm) are found in the region of the shoulder and
pelvic girdle.”

So, Rossi et al reported some soft tissues are real, but labeled others as “fake”. The latter imputes unsavory motives, typically for profit, without producing evidence of such motives. Always ask yourself: Cui bono? = who benefits?

Consider the possibility that Tridentinosaurus is what it is: a mold fossil poorly preserving a few bones and patches of scaly skin on a headless overall outline (Fig 1).

In other words, Tridentinosaurus is real, not a forgery. It is a crappy fossil from a stratum that rarely produces fossils. That makes it a precious, rare specimen, not a forgery. Don’t cancel or dismiss it. The LRT tests many such crappy taxa. Use what you have, especially when “we’ve never found anything else like it.”  ; – )

Going full circle and getting back to the misleading Nature ScienceAlert headline,
go ahead and glean whatever you can from Tridentinosaurus. Then add those few scores to your own wide gamut phylogenetic analysis. Don’t dismiss it and avoid analysis. Be the scientist who, “finally reveals its true identity.”

Then let us know what you get.

References
Dal Piaz Gb. 1932 (1931). Scoperta degli avanzi di un rettile (lacertide) nei tufi compresi entro i porfidi quarziferi permiani del Trentino. Atti Soc. Ital. Progr. Scienze, XX Riunione, v. 2, pp. 280-281. [The discovery of the remains of a reptile (lacertide) in tuffs including within the Permian quartz porphyry of Trentino.]
Leonardi P 1959. Tridentinosaurus antiquus Gb. Dal Piaz, rettile protorosauro permiano del Trentino orientale. Memorie di Scienze Geologiche 21: 3–15.
Ronchi, A., Sacchi, E., Romano, M., and Nicosia, U. 2011. A huge caseid pelycosaur from north−western Sardinia and its bearing on European Permian stratigraphy and palaeobiogeography. Acta Palaeontologica Polonica 56 (4): 723–738.
Rossi V et al. 2021. New analyses of the “soft tissues” of the Italian tetrapod Tridentinosaurus antiquus. Insight on taphonomy and conservation history. EAVP abstract 2021.
Rossi V et al (6 co-authors) 2024. Forged soft tissues revealed in the oldest fossil reptile from the early Permian of the Alps. Palaentology https://doi.org/10.1111/pala.12690.