Fig 1.
JME 3995, Thalassochelydia indet., Late Jurassic (early Tithonian) of Birkhof, Bavaria, Germany.
Photograph (top) and interpretive line drawing (bottom) in ventral view. Hatched areas denote bones. Roman numerals denote digit identity. Note large patches of scaly skin preserved across the specimen. For additional images, please see S1 Appendix. Abbreviations: fe, femur; ti, tibia.
Fig 2.
NKMB Watt18/211, Thalassemys bruntrutana, Late Jurassic (early Late Kimmeridgian) of Wattendorf, Bavaria, Germany.
Photograph (left) and interpretive line drawing (right) of specimen in ventral view. Roman numerals denote digit identity, Arabic numerals vertebral identity. Abbreviations: Ab, abdominal scute; ce, cervical vertebra; cen, centrale; co, coracoid; col, cololite (cololith); cr, costal rib; epi, epiplastron; Fe, femoral scute; fe, femur; fi, fibula; hu, humerus; hyo, hyoplastron; hyp, hypoplastron; il, ilium; Im, inframarginal scute; int, intermedium; is, ischium; nu, nuchal; Pe, pectoral scute; per, peripheral; pu, pubis; py, pygal; ra, radius; sc, scapula; spy, suprapygal; ti, tibia; tr, thoracic rib; ul, ulna; uln, ulnare; xi, xiphiplastron.
Fig 3.
NKMB Watt18/211, Thalassemys bruntrutana, Late Jurassic (late Kimmeridgian) of Wattendorf, Bavaria, Germany.
Photographs taken under UV light. (A) right forelimb, (B) skull and neck, (C) left forelimb, (D) right hind limb, (E) tail, and (G) left hind limb in ventral view. White arrows highlight soft tissue. Yellow arrows indicate epibionts. For anatomical interpretation of vertebral column and limb, please refer to Fig 2. Abbreviations: cb, ceratobranchial; ch, ceratohyal; de, dentary; ex, exoccipital; ju, jugal; mx, maxilla; pa, parietal; qj, quadratojugal; so, supraoccipital; sur, surangular.
Table 1.
A selection of basic measurement of NKMB Watt18/211.
Fig 4.
Strict consensus of 5940 MPTs of 1743 steps showing the phylogenetic placement of Thalassemys bruntrutana as well as important clades and taxa discussed in the text.
Note that terminal clades in bold were been collapsed to save space (see S4 Appendix for full topology). Important internal nodes are labelled. ‘Plesiochelydidae’ is placed in single quotes to indicate that is does not have a formal phylogenetic definition. ‘Macrobaenidae’ is also placed in single quotes because the specifier for this clade, Macrobaena mongolica, is not included. However, the respective taxa are commonly labelled as ‘macrobaenids’ in the literature.
Fig 5.
The relative length of the humerus, ulna, and hand of Thalassemys bruntrutana relative to that of extant turtles.
In the diagram to the front, extant turtles are color coded for taxonomic groups, in the diagram to the back, extant turtles are color coded for habitat preferences. All data of extant turtles are taken from Joyce and Gauthier (2004) [11]. Note that Thalassemys bruntrutana has relatively longer hand that extant trionychids, but shorter hands that extant carettochelyids and chelonioids.
Fig 6.
The comparative anatomy of the skin of the limbs of extant turtles.
(A) the testudinid tortoise CAS 165598 Psammobates oculifera, an inhabitant of desserts. (B) the trionychid turtle CAS 65705 Apalone spinifera, an inhabitant of rivers. (C) the emydid turtle CAS 13889 Chrysemys picta, an inhabitant of ponds. (D) the cheloniid turtle CAS 8478 Chelonia mydas, an inhabitant of oceans.
Fig 7.
Taphonomic preservation of freshwater adapted turtle forelimbs in dorsal view.
(A) the carettochelyid Allaeochelys crassesculpta from the Eocene Messel Formation of Germany (IRSNB AFR34). (B) the pan-trionychid Perochelys lamadongensis from the early Cretaceous Jehol Biota of China (IVPP V 18048). (C) the testudinoid turtle Echmatemys sp. (FOBU 14014) from the Green River Formation of the USA. (D) Parachelys sp. (NKMB Watt05/202) from the Late Jurassic of Wattendorf, Germany. Note that the forelimb is slightly adducted in all cases and that the digits are stacked on top of one another. The images are not to scale.
Fig 8.
Comparisons of forelimbs of marine adapted turtles.
(A) photograph and (B) line drawing of reflected left flipper of the extant leatherback turtle Dermochelys coriacea (QM J47453) in dorsal view. (C) photograph and (D) line drawing of right flipper of the extinct chelonioid Allopleuron hofmanni (NHMUK PV 42893) in dorsal view. (E) photograph and (F) line drawing of the right flipper of the extant cheloniid Natator depressus (QM J14463) in dorsal view. (G) photograph and (H) line drawing of right flipper of the extinct protostegid Rhinochelys nammourensis (MSNM V3933; picture courtesy of Ren Hirayama) in dorsal view. (I) photograph and (J) line drawing of reflected left flipper of the extinct thalassochelydian Thalassemys bruntrutana (NKMB Watt18/211) in ventral view. Roman numerals denote digit identity. Abbreviations: c, central carpal; dc, distal carpal; i, intermedium; mc, metacarpal; p, pisiform; r, radiale; ra, radius; u, ulnare; ul, ulna.