Testudo (Chersine) kalksburgensis Toula 1896
Creators: name: Luján, Àngel H.
name: Čerňanský, Andrej
name: Bonilla-Salomón, Isaac
name: Březina, Jakub
name: Ivanov, Martin
Publisher: name: Zenodo
Year: 2021
Subjects: Biodiversity
Taxonomy
Animalia
Chordata
Reptilia
Testudines
Testudinidae
Testudo
Testudo kalksburgensis

description: Testudo (Chersine) cf. kalksburgensis Toula, 1896
(Figs 5; 6)
LOCALITIES. — MWQ1/2001, MWQ2/2003, MWQTC/2001, MWQ4/2018 and MCQ3/2005.
STUDIED MATERIAL. — Czech Republic. South Moravia Region, Mokrá-Quarry, carapace remains (Fig. 5 A-V’): Pal. 1319, nuchal; Pal. 1320, nuchal; Pal. 1321, nuchal; Pal. 1322, neural 4; Pal. 1323, neural 6; Pal. 1350, neural 7; Pal. 1322, neural 4; Pal. 1324, pygal; Pal. 1325, pygal; Pal. 1328, right costal 1; Pal. 1326, left costal 1; Pal. 1327, left costal 1; Pal. 1329, right costal 2; Pal. 1330, left costal 3; Pal. 1331, left costal 6; Pal. 1332, left peripheral 1; Pal. 1333, right peripheral 1; Pal. 1334, left peripheral 2; Pal. 1335, left peripheral 2; Pal. 1336, right periph- eral 2; Pal. 1337, right peripheral 2; Pal. 1338, right peripheral 5; Pal. 1339, left peripheral 7; Pal. 1340, right peripheral 7; Pal. 1341, right peripheral 8; Pal. 1342, left peripheral 9; Pal. 1343, right peripheral 9; Pal. 1344, left peripheral 10; Pal. 1345, left peripheral 10; Pal. 1346, left peripheral 10; Pal. 1347, left peripheral 11; Pal. 1348, left peripheral 11. Pal. 1349, left peripheral 11. Plastral remains (Fig. 6 A-H’): Pal. 1351A, left epiplastron; Pal. 1352, entoplastron; Pal. 1353, entoplastron; Pal. 1354, entoplastron; Pal. 1351B, right hyoplastron; Pal. 1355, right hyoplastron; Pal. 1356, left hypoplastron; Pal. 1357, right hypoplastron; Pal. 1358, right hypoplastron; Pal. 1359, right hypoplastron; Pal. 1360, left xiphiplastron; Pal. 1361, left xiphiplastron; Pal. 1362, left xiphiplastron.
DESCRIPTION
Testudo material recovered from Mokrá-Quarry consists mainly of disarticulated plates (Pal. 1319-1362). However, some costals, peripherals and neurals are missing. They belong to a medium-sized Testudo, which reached approximately 20-25 cm. The following description is based on the entire available material, but not all the plates are depicted (Figs 5; 6). Most of the dermal grooves and sutures are visible. There is no ornamentation on the carapace or plastron. Growth lines are discernible in some carapace plates, and more specifically in both peripheral and costal plates (e.g., Fig. 5K, A’).
The nuchal plate is hexagonal, slightly wider than long, and its anterior edge is pointed (Fig. 5 A-D). The posterolateral edges are straight, whereas the anterior ones are curved in medial direction. A transverse thickening is recognizable on the visceral surface of the nuchal (Fig. 5C, D). The cervical scute is longer than wide and its total length constitutes less than a half of the nuchal plate. It is well developed both dorsally and viscerally according to the three preserved plates (Pal. 1319-21). The anterior edge is narrower than the posterior ones. The lateral sulci are almost straight and parallel to each other (Fig. 5A, B).
Only three neurals plates are preserved, which vary in shape from subsquare (i.e., neural 4) to hexagonal (i.e., neurals 6 to 7: Fig. 5 E-G). It is noteworthy that none of them is more than twice as wide as long, and that they are encroached transversally by the intervertebral sulci (Fig. 5 E-G).
The pygal plate is trapezoidal with slightly concave anterolateral margins. Its external surface is moderately convex, whereas its internal one is rather concave (Fig. 5 H-J). The marginal scutes 12 are missing, and therefore the supracaudal scute is not divided by a sagittal groove (Pal. 1324-25: Fig. 5 H-J). The shape of the vertebral scutes cannot be ascertained with a confidence because they are incomplete.
Only five of the eight costal plates are present (i.e., costals 1-3 and 5-6), which are trapezoidal. Costals 1 and 3 host the intervertebral sulci (Fig. 5K, L, O, P, W’), whereas the costals 2 and 6 host the interpleural sulci (Fig. 5M, N, Q, R, W’). The pleural scutes are poorly preserved, so no significant details can be discerned. Despite this, the pleuromarginal sulcus coincides with the costoperipheral suture all along the preserved peripheral and costal plates (e.g., Fig. 5K, L, W’).
Peripheral plates 1-3, together with the nuchal, make up the anterior opening of the shell. Peripheral 1 is heptagonal, while the peripheral 2 is subtriangular. Peripheral 1 displays a moderately developed spike at about the middle of the anterior edge. The presence of protrusions on the remaining peripherals (i.e., 2 and 3) cannot be evaluated. Peripheral 5 (Pal. 1338: Fig. 5 A’, B’), which is the only preserved plate involved in the shell bridge, is rectangular and rather flat, unlike posterior peripherals. Pal. 1338 displays a very weak longitudinal lateral ridge that is placed slightly above of the marginoabdominal sulcus. Peripherals 7 - 11 (Fig. 5 C’-W’), together with the pygal plate (Fig. 5 H-J), form the posterior opening of the shell. An elongated and subvertical scar of the dorsal projection of the hypoplastron is discernible in peripheral 7 internally (Fig. 5 E’, F’). As a rule, the peripherals 8-10 in Testudo are rectangular with dorsal surfaces slightly concave, whereas in Ptychogaster, they are rather subrectangular and the dorsal concavity is well-developed. Peripheral 11 hosts the lateral edge of the supracaudal scute (Fig. 5 S’-W’). The marginal scute 1 is trapezoidal, whereas the remaining posterior marginals are either subsquare or subrectangular (Fig. 5 A-D, S-V, W’). Based on two nuchal plates (Pal. 1319-21), two peripherals 1 (Pal. 1332-33) and three costals 1 (Pal. 1326-28), the triple junction amongst the pleural 1, vertebral 1, and marginal 1 is located outside the nuchal plate. Noticeably, the posterior border of the marginal 5 (Pal. 1338; Fig. 5 A’, B’) is parallel (i.e., instead of oblique) relative to those anteroposterior edges of the peripheral 5.
A partial epiplastron, together with the hyoplastron (Fig. 6 A-F, O-R), forms the anterior plastral lobe, which is rather trapezoidal (Fig. 6 I’). Despite not being entirely preserved, the epiplastral dorsal pad seems rectangular and longer than wide. It is moderately developed posteroventrally and overhangs it slightly. Consequently, a small gular pocket is present (Fig. 6 A-C). The gular scutes are triangular, with slightly sinuous lateral margins, and form an angle of less than 45° relative to the sagittal axis (Fig. 6 B-D).
The three available entoplastra (Pal. 1352-54: Fig. 6 G-N) are hexagonal both ventrally and viscerally. They are partially covered by the gular scutes, which generally extend up to the middle of the entoplastron. The ventral surface of the epiplastra, covered by the gular scutes, is not in relief. In all specimens, the gular scutes are not crossed by the humeropectoral sulcus transversally (Fig. 6H, I, K, L).
Pal. 1351B is the best preserved hyoplastron (Fig. 6 O-R), which hosts entirely both the humeropectoral and pectoroabdominal scutes: the former is nearly straight and obliquely oriented relative to the sagittal plane (i.e., only slightly sinuous: Fig. 6R), while the latter is curved and transversally oriented relative to the sagittal plane (Fig. 6R, V). The preserved portion of the humeral scute indicates that this was trapezoidal. The abdominal seems to be the largest scute of the plastron. Moreover, its medial sector is slightly oblique (Fig. 6 Y-Z). The hypo-xiphiplastral suture is roughly straight and well developed, which means that a plastral hinge is absent. The xiphiplastron is trapezoidal and its ventral side is very flat and crossed by the femoroanal sulcus (Fig. 6 A’-C’). It is noteworthy that the distinct notch in their lateral margins, between the anal and femoral scutes, is missing(Fig. 6 A’, C’). The femoral is trapezoidal and much longer medially than the anal scutes, which are subrectangular and wider than long. The femoroanal sulcus is slightly sinuous and obliquely oriented relative to the sagittal plane. The anal notch is wider than long, and its visceral area covered by the anal scutes is variable, from moderately (Pal. 1361: Fig. 6 A’, B’) to well developed (Pal. 1362: Fig. 6 E’, F’).
REMARKS
The genus Testudo s.l. is a clade with five extant and multiple extinct species of terrestrial tortoises of western Palearctic distribution (Lapparent de Broin et al. 2006a, b; Fritz & Bininda-Emonds 2007; Corsini et al. 2014; Delfino et al. 2012; Luján et al. 2016). Despite that, in the past, three extant genus-group taxa were distinguished as genera (see e.g., Turtle Taxonomy Working Group 2014), currently, the use of a single genus (Testudo s.l.) and three subgenera (Testudo, Agrionemys and Chersine) is being better accepted (see Luján et al. 2016; Graciá et al. 2017; Turtle Taxonomy Working Group 2017). Among extinct taxa, the taxonomy of Testudo s.l. also included the distinction of the extinct genus Paleotestudo Lapparent de Broin, 2000. Although the latter has not been the object of an exhaustive review, results presented by Luján et al. (2016) clearly pointed out that Paleotestudo is a junior subjective synonym of subgenus Chersine.
Regarding the species Testudo kalksburgensis Toula, 1896, it was originally described by Toula (1896) based on one specimen from Kalksburg, Vienna: a partial shell currently housed at the IGUW. At the beginning of the twentieth century, new fragmentary material, coming from the late Miocene locality of Au am Leithaberge, was referred to T. kalksburgensis by Siebenrock (1914). Shortly after, Staesche (1931) also erected Testudo kalksburgensis var. steinheimensis based on various specimens from the middle Miocene (MN7) locality of Steinheim (Germany). Although T. kalksburgensis was considered a junior subjective synonym of T. antiqua Bronn, 1831 by Glaessner (1933), subsequently Młynarski (1976) resurrected the species once again. Indeed, the validity of T. kalksburgensis was also confirmed by latter studies (see Młynarski 1980; Bachmayer & Młynarski 1981; Schleich 1981; Gemel & Rauscher 2000; Gemel 2002; Danilov et al. 2012; Luján et al. 2016; Březina et al. 2021).
description: Published as part of Luján, Àngel H., Čerňanský, Andrej, Bonilla-Salomón, Isaac, Březina, Jakub & Ivanov, Martin, 2021, Fossil turtles from the early Miocene localities of Mokrá-Quarry (Burdigalian, MN 4), South Moravian Region, Czech Republic, pp. 691-707 in Geodiversitas 43 (20) on pages 699-700, DOI: 10.5252/geodiversitas2021v43a20, http://zenodo.org/record/5679113