TABLE 1. Measurements of the main carapace armour in cyamodontoid placodonts. All values are based on straight measurements (rounded to the nearest full millimetre), not including carapace curvature. *: The carapace of Placochelys placodonta Jaekel, 1902 consists only of few fragments thus the given ratio is solely based on the interpretative drawing of the animal by Jaekel (1907: plate 10). Note that specimens MCSNB 8358 and BSP AS I 8 may give LC/WC ratios which are too low, based on their flattened taphonomic preservation.

 

Taxon and accession number

Length of carapace
(LC)

Width of carapace (WC)

Ratio LC/WC

Measurements obtained from:
 

Cyamodus hildegardis
 (PIMUZ T58)

~215 mm / ~205 mm

~230 mm / ~215 mm

~0.93 / ~0.95

specimen, Figure 2 / Figure 10.1 (this paper)
 

Glyphoderma kangi
(ZMNH M 8729)

243 mm

262 mm

0.93

Zhao et al. (2008, figure1, table 1)
 

Henodus chelyops
(GPIT uncat., “specimen no. 3”)

640 mm

830 mm

0.77

Huene (1938, figures 5, 6, table); cast (this paper)
 

Placochelys? minutus
(Gmr005)

142 mm

136 mm

1.04

Yin et al (2000, p. 12); see also Li and Rieppel (2002b, p. 407)
 

Placochelys placodonta
 (FAFI)

-

-

1.4* (7:5)

Jaekel (1907, plate 10)
 

Psephoderma alpinum
 (MCSNB 8358)

207 mm / 210 mm

254 mm / 253 mm

0.81 / 0.83

Pinna and Nosotti (1989, plate XXIX, p. 35) / Rieppel (2002, p. 16)
 

Psephoderma alpinum
(MSNM V527)

250 mm

225 mm

1.11

Pinna and Nosotti (1989, plate XXVI, p. 35)
 

Psephoderma alpinum
(BSP AS I 8)

375 mm / 375 mm

423 mm / 425 mm

0.89 / 0.88

Meyer (1858, plate 29, p. 246) / Rieppel (2002, p. 14)
 

Psephochelys polyosteoderma
 (IVPP V 12442)

265 mm

271 mm

0.98

Li and Rieppel (2002a, p. 157; 2002b, p. 404)
 

Sinocyamodus xinpuensis
 (IVPP V 11872)

130 mm

175 mm

0.74

Li (2000, plate 1); Li and Rieppel (2002b, p. 407)