Plateosaurus trossingensis Fraas, 1913

Fernández, Omar Rafael Regalado, Stöhr, Henrik, Kästle, Benedikt & Werneburg, Ingmar, 2023, Diversity and taxonomy of the Late Triassic sauropodomorphs (Saurischia, Sauropodomorpha) stored in the Palaeontological Collection of Tübingen, Germany, historically referred to Plateosaurus, European Journal of Taxonomy 913 (1), pp. 1-88 : 62-64

Plateosaurus trossingensis Fraas, 1913

Figs 6 , 7 , 24, 30

Plateosaurus quenstedti von Huene, 1905: 348 .

Type material

Holotype

GERMANY • almost complete skeleton; Obere Mühle , Trossingen Formation; SMNS 13200 .

Material examined

We treat the following specimens as comparable to Plateosaurus trossingensis but with distinctive morphotypes:

“ GPIT I” ( Fig. 24 )

GERMANY – Obere Mühle, Trossingen Formation • mounted skeleton in the collection, comprises most of the skeleton, and several cast elements, including a cast of the skull of SMNS 13200 ; GPITPV-30784 • original skull of the skeleton embedded partially in matrix; GPIT-PV- 111840 • left maxillary; GPIT-PV- 111842 • left squamosal; GPIT-PV- 111848 • left postorbital; GPIT-PV- 111849 • left jugal; GPIT-PV- 111845 • left quadratojugal; GPIT-PV- 111846 • left quadrate; GPIT-PV- 111847 • right quadrate; GPIT-PV- 111852 • right squamosal; GPIT-PV- 111853 • right postorbital; GPIT-PV- 111854 • right jugal; GPIT-PV- 111850 • right quadratojugal; GPIT-PV- 111851 • hyoid and tongue bones still in the matrix; GPIT-PV- 60260 • capitulum and tuberculum of a thoracic rib; GPIT-PV- 60257 • fragment of the neural arch of a caudal vertebra; GPIT-PV- 60256 • right distal carpal; GPIT-PV- 60338 • right manual phalanx; GPIT-PV- 60274 • right manual phalanx; GPIT-PV- 60275 • right manual phalanx; GPIT-PV- 60276 • right manual phalanx; GPIT-PV- 60277 • right manual phalanx; GPIT-PV- 60278 • right manual claw; GPITPV-60339 • left distal phalanx of manual digit V; GPIT-PV- 60337 • left manual phalanx; GPIT-PV- 60253 • right distal tarsal; GPIT-PV- 60254 • six distal caudal vertebrae with three chevrons; GPIT-PV- 60223 .

Note: Plateosaurus trossingensis , gracile and medium-sized morphotype. This specimen was referred to as Pl. ‘ quenstedti ’ ( von Huene 1932).

“ GPIT VI ” ( Fig. 30 )

GERMANY – Obere Mühle, Trossingen Formation • a right femur, a right tibia, a right fibula, a right astragalus, a complete set of the right metatarsals and pedal phalanges, still embedded in the matrix; GPIT-PV- 30789 .

Note: Plateosaurus cf. trossingensis , gracile and medium-sized morphotype. Von Huene also referred to this specimen as Pl. ‘ quenstedti ’.

“ GPIT A” ( Figs 6–7 )

GERMANY – Pfrondorf, (?) Trossingen Formation • atlas; GPIT-PV- 60168 • axis; GPIT-PV- 60162 • anterior cervical 5; GPIT-PV- 60164 • posterior cervical 8; GPIT-PV- 60155 • posterior cervical 9; GPITPV-60156 • anterior dorsal 4(?); GPIT-PV- 60154 • fragment of the neural arch of posterior dorsal 14(?); GPIT-PV- 60159 • left scapula; GPIT-PV- 60152 • right ulna; GPIT-PV- 60172 • left ulna; GPIT-PV- 60163 • right pubis; GPIT-PV- 60153 • left femur with a reconstructed shaft; GPIT-PV- 60151 • proximal portion of right femur; GPIT-PV- 60150 • left fibula; GPIT-PV- 60170 • proximal and distal ends of metatarsal II; GPIT-PV- 60165 • proximal and distal ends of metatarsal III; GPIT-PV- 60171 • pedal ungual III with the distal end of phalanx III.3; GPIT-PV- 60161 • possibly pedal phalanx IV.2; GPIT-PV- 60157 • possibly pedal phalanx IV.3; GPIT-PV- 60158 • casts of axis; NHMUK PV R 3062 • cervical vertebra 5; NHMUK PV R 3063 • cervical vertebra 7; NHMUK PV R 3064 • cervical vertebra 8; NHMUK PV R 3065 • left pubis; NHMUK PV R3067 • right pubis NHMUK PV R 5845 • both ischia; NHMUK PV R 3066 • left ulna; NHMUK PV R 3071 • left radius; NHMUK PV R 3074 • left femur; NHMUK PV R 3068 • proximal part of the left tibia; NHMUK PV R 5849 • left fibula; NHMUK PV R 3070 • two phalanges; NHMUK PV R 3075 • left metatarsal; NHMUK PV R 3073 • left metatarsal; NHMUK PV R 3073 • claw; NHMUK PV R 3076 .

Note: Plateosaurus cf. trossingensis , a gracile and medium-sized morphotype, holotype of Pl. ‘ quenstedti ’. The GPIT Collection still houses some of the holotype material. However, four cervical vertebrae, a left scapula, two humeri, a radius, the posterior half of the dorsal series, the sacrum, the ilia, the ischia, the right pubis, the left tibia, and the metatarsals are currently lost – the NHMUK in London houses casts of some of these elements.

Remarks

“GPIT I” is referred to as Pl. trossingensis (species 8 in Fig. 3 ); it is worth noting that a considerable amount of intraspecific variability between the specimens that make Pl. trossingensis needs to be studied in detail. The rest of the material from the Obere Mühle is considered as Pl. cf. trossingensis based on the stratigraphic framework that has been currently proposed for the Trossingen outcrop. Von Huene (1929, 1932) formulated the taxonomy of sauropodomorphs from the Late Triassic more akin to the polytypic approach, where morphotypes are used as criteria to produce what in modern usage would be equivalent to a subspecies. The specimen “GPIT A” from Pfrondorf (label c in Fig. 1 ), the holotype of Plateosaurus ‘ quenstedti ’ (species 3 in Fig. 3 ), shares several similarities in the ulna, the ilium and the femoral head morphology with GPIT-PV-30784. The holotype of Pl. ‘ quenstedti ’, however, is now incomplete, with several elements lost, although casts of most of these elements are now available in the Natural History Museum. Given these circumstances, it is reasonable to consider Pl. ‘ quenstedti ’ as a senior subjective synonym of Pl. trossingensis . Furthermore, if future studies conclude that the disparity between the holotype of Pl. trossingensis and GPIT-PV-30784 is substantial enough to warrant the recognition of a new species, then GPIT-PV-30784 can bear the name Pl. ‘ quenstedti ’ of which GPIT-A would be the holotype.

Figures

Fig. 6. “GPIT A” and “GPIT D” mounted by von Huene in 1901, in right anterolateral view. The mount, which for reference has the number GPIT-PV-60296, was disassembled in the second half of the 20th century. Photo from University Archive Tübingen, catalogue number of the photo: UAT 678/73; background changed by the authors.

Fig. 7(see next page). Holotype of Plateosaurus ‘quenstedti’ described by von Huene (1907) and illustrated on the reconstruction of Plateosaurus ‘quenstedti’ redrawn from von Huene (1907: pl. 102). A. GPITPV-60168, atlas in ventral view. B. GPIT-PV-60162, axis in left lateral view. C. GPIT-PV-60164, cervical 5 in left lateral view. D. GPIT-PV-60156, centrum of putative cervical 6 in right lateral view. E. GPITPV-60155, partial cervical 8 in left lateral view. F. GPIT-PV-60154, anterior dorsal (presumed dorsal 4) in left lateral view. G. GPIT-PV-60152, left scapula in medial view. H. GPIT-PV-60159, postzygapophyses attached to the prezygapophyses of dorsal vertebra (presumed dorsal 14) in posterior view. I. GPITPV-60153, right pubis in anterior view. J. GPIT-PV-60151, left femur, reconstructed shaft, in posterior view. K. GPIT-PV-60172, right ulna in anterolateral view. L. GPIT-PV-60163, left ulna in anterolateral view. M. GPIT-PV-60150, proximal half of the right femur in posterior view. N. GPIT-PV-60170, left fibula in lateral view. O. GPIT-PV-60165, proximal and distal ends of metatarsal II in posterior view. P. GPIT-PV-60171, proximal and distal ends of metatarsal III in posterior view. Q. GPIT-PV-60161, pedal ungual III with distal end of phalanx III.3 in lateral view. R. GPIT-PV-60157, phalanx, presumed pedal phalanx IV.2 in dorsal view. S. GPIT-PV-60158, phalanx, possibly pedal phalanx IV.3 in dorsal view. The human skeleton represents a height of 1.75 m, as originally drawn by von Huene (1907: pl. 102), the relative size of the reconstructed sauropodomorph is 2 m. Reconstruction and photographs made by the authors, with photos taken on the labelled side or on the side that was illustrated in the past.

Fig. 24 (see next page). Skeletal elements of specimen GPIT-PV-30784 historically known as “GPIT I”. A–B. GPIT-PV-111840, skull. A. In left lateral view. B. In right lateral view. C. GPIT-PV-60260, hyoid bones. D. GPIT-PV-60336, sternal plates. E. GPIT-PV-60223, six distal caudals with chevrons. F. GPIT- PV-60256, half of a distal caudal. G. GPIT-PV-60223, four distal caudals with chevrons. H. GPIT- PV-60257, capitulum and tuberculum of left dorsal 15. I. GPIT-PV-60274, manual phalanx. J. GPIT- PV-60275, manual phalanx. K. GPIT-PV-60276, manual phalanx. L. GPIT-PV-60339, ungual I.1. M. GPIT-PV-60254, distal tarsal. N. GPIT-PV-60253, manual phalanx. O. GPIT-PV-60277, manual phalanx. P. GPIT-PV-60278, manual phalanx. Q. GPIT-PV-60337, manual phalanges V.1 and V.2. R. GPIT-PV-60338, distal carpal. S. Mounted skeleton, photograph taken in the ca 1960 (archive photo UAT 678/73); the skull on display is a cast from the skull of specimen SMNS 13200.

Fig. 30. Skeletal elements of specimen GPIT-PV-30789 on display in the diorama, referred to as Plateosaurus ‘quenstedti’ by von Huene (see Fig. 14) comprising a right hindlimb, with a femur, a tibia, a fibula, and a complete pes.

Fig. 3. Timeline showing changes in the taxonomic placement of the specimens of early-diverging sauropodomorphs considered to be Plateosaurus Meyer, 1837 from 1900 to 2004. This timeline considers only papers discussing taxonomy and papers describing and naming new species. Lines indicate continuity or change in specimen composition of species across revisions. Arrows outside the timeline indicate that the taxa were named before 1900 and/or are still valid after 2004. When more lines depart from one node, part of the specimens included in that species were referred to as different species. Lines converging in one node indicate that the specimens were lumped together into the species in the node. Stars at the end of a line indicate that in the taxonomic revision, the name became either a nomen dubium or a nomen nudum. Lines continuing after this point indicate that the specimens were referred to the new node. This timeline does not include specimens removed from the genus Plateosaurus, namely Efraasia (von Huene, 1907–1908), Ruehleia Galton, 2001, Camelotia Galton, 1985 and Tuebingosaurus Regalado Fernández & Werneburg, 2022. The green lines correspond to species that have been synonymized withPl. trossingensisFraas, 1913, and the blue lines correspond to those that have been synonymized with Pl. gracilis(von Huene, 1905). The orange-red lines refer to species removed from Sauropodomorpha Huene, 1932 altogether. Changes after 2004 are discussed in the text.

Fig. 1. Map showing the city of Tübingen, Baden-Württemberg, in the centre of the localities of the specimens described in this paper. The second map places Baden-Württemberg within Germany. The timeline shows the chronology in which the specimens were first excavated but not described. The date of the excavation of ‘Zanclodon’ is the only one that is not certain (see Results – Mid-19th century). Map data: Google, GeoBasis-DE / BKG.