Scaphognathus soft tissue in RTI, PTM and UV

Jäger et al. 2019
present a new look at the holotype of Scaphognathus and pay homage to its first describer, Goldfuß 1831. Soft tissue is hard to see in this specimen, whether in white light, UV light or using RTI/PTM (Reflectance Transformation Imaging (see below references) and Polynomial Texture Mapping) methods.

Figure 1. Scaphognathus SIPB Goldfuß 1304a, no. 109 in the Wellnhofer 1970 catalog. Two plates drawn by Goldfuß. Color tracing here. Note the foot and prepubis were overlooked by all prior workers.

Figure 1. Scaphognathus SIPB Goldfuß 1304a, no. 109 in the Wellnhofer 1975 catalog. Plate and counter plate drawn by Goldfuß. UV images from Jäger et al. 2019. Color tracing here. Note the foot and prepubis were overlooked by all prior workers. Note the Goldfuss drawing includes ‘fluff’ over the dorsal vertebrae confirmed by Jäger et al.

Previously I reported
plumes (pycnofibers) emanating from the dorsal region of several pterosaurs, like Jeholopterus (Fig. 5), homologous with those found in Longisquama and Cosessaurus. No one supported these observations in pterosaurs until now (Fig. 2). In fact, this is one of the reasons why workers think I am ‘seeing things’ that others cannot see. So this is confirmation not only of my own observations, but also, as noted in the text, those of Goldfuiß 1833, which have been ignored until this paper.

Figure 4. Jäger et al identify this area as 'dorsal pycnofibers.'

Figure 2. Jäger et al identify this area as ‘dorsal pycnofibers.’I have attempted to trace in color the shapes I see here, Not all the plumes are identified here.

It would be worthwhile
to review Darren Naish’s blogpost that ridiculed my observations of dorsal plumes, now confirmed by several pterosaur specimens.

Figure 2. Reconstruction of Jeholopterus. This owl-like bloodslurper was covered with super soft pycnofibers to make it a silent flyer.

Figure 3. Reconstruction of Jeholopterus. This owl-like bloodslurper was covered with super soft pycnofibers to make it a silent flyer.

Phylogenetic bracketing indicates
that soft tissue fibers/plumes emanating from the dorsal region are present in a wide range of basal pterosaurs, up to the Early Cretaceous. Such plumes likely reduced the speed that these pterosaurs could fly, and reduced the noise they made while flying, as in similarly fluffy owls.

Figure 1. Click to enlarge. The origin and evolution of Longisquama's "feathers" - actually just an elaboration of the same dorsal frill found in Sphenodon, Iguana and Basiliscus. Here the origin can be found in the basal tritosaur squamate, Huehuecuetzpalli and becomes more elaborate in Cosesaurus and Longisquama.

Figure 4. The origin and evolution of Longisquama’s “feathers” – actually just an elaboration of the same dorsal frill found in Sphenodon, Iguana and Basiliscus. Here the origin can be found in the basal tritosaur squamate, Huehuecuetzpalli and becomes more elaborate in Cosesaurus and Longisquama.

We looked at this Scaphognathus specimen earlier
here when the tiny foot was first discovered. That foot was overlooked by the Jäger et al. team, but I thank them for confirming, without citation, the presence of dorsal plumes in this pterosaur.

Figure 1. Bergamodactylus compared to Cosesaurus. Hypothetical hatchling also shown.

Figure 5 Bergamodactylus compared to Cosesaurus. Hypothetical hatchling also shown. Dorsal frills are visible in the fossil of this pterosaur, too.


References
Goldfuss GA 1830. Pterodactylus crassirostris. Isis von Oken, Jena pp. 552–553.
Jäger KRK, Tischlinger H, Oleschinski G and Sander PM 2019. Goldfuß was right: Soft part preservation in the Late Jurassic pterosaur Scaphognathus crassirostris revealed by reflectance transformation imaging (RTI) and UV light and the auspicious beginnings of paleo-art. Palaeontologia Electronica: 21.3.4T
https://doi.org/10.26879/713
Wellnhofer P 1975a. Teil I. Die Rhamphorhynchoidea (Pterosauria) der Oberjura-Plattenkalke Süddeutschlands. Allgemeine Skelettmorphologie. Paleontographica A 148: 1-33.1975b. Teil II. Systematische Beschreibung. Paleontographica A 148: 132-186. 1975c. Teil III. Paläokolgie und Stammesgeschichte. Palaeontographica 149: 1-30.

wiki/Scaphognathus
https://palaeo-electronica.org/-scaphognathus-in-rti-and-uv


Notes about RTI:
Bogart J 2013a. Reflectance Transformation Imaging: Guide to Highlight Image Capture. Cultural Heritage Imaging, San Francisco. http://culturalheritageimaging.org/What_We_Offer/Downloads/RTI_Hlt_Capture_Guide_v2_0.pdf
Bogart J 2013b. Reflectance Transformation Imaging: Guide to RTIViewer. Cultural Heritage Imaging, San Francisco. http://culturalheritageimaging.org/What_We_Offer/Downloads/rtiviewer/RTIViewer_Guide_v1_1.pdf

wiki/Scaphognathus

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