Phylogenetic Systematics of I guanine Lizards 103 



54. Hyoid n (Fig. 33): (A) second ceratobranchials in medial contact with one another 

 for most or all of their lengths; (B) separated from one another medially for most or all of 

 their lengths. 



55. Neural spines of presacral vertebrae (Figs. 34, 35): (A) tall, making up more than 

 50% of the total vertebral height; (B) short, making up less than 50% of the total vertebral 

 height. 



56. Zygosphenes (Fig. 36): (A) connected to prezygapophyses by a continuous arc of 

 bone; (B) separated from zygapophyses by a deep notch. 



57. Sacrum I: (A) posterolateral processes of second pleurapophyses (usually) 

 present; (B) (usually) absent. 



58. Sacrum II: (A) foramina in the ventral surfaces of the second pleurapophyses 

 (usually) present; (B) (usually) absent. 



59. Number of caudal vertebrae: (A) more than 40; (B) fewer than 40. 



60. Autotomy septa in caudal vertebrae: (A) present (Fig. 37); (B) absent. 



61. Beginning of the autotomic series of caudal vertebrae or beginning of the series of 

 caudal vertebrae with two pairs of transverse processes (Fig. 37): (A) at or before the 10th 

 caudal vertebra; (B) at or behind the 10th caudal vertebra. 



62. Thin, midsagittal processes on the dorsal surface of the caudal centra anterior to the 

 neural spines (Fig. 38): (A) relatively large and present well beyond the anterior third of 

 the caudal sequence; (B) relatively small and confined to the anterior fifth of the caudal 

 sequence. 



63. Postxiphistemal inscriptional ribs: (A) do not form continuous chevrons (Fig. 39); 

 (B) variably form continuous chevrons; (C) invariably form continuous chevrons. 



64. Suprascapulae: (A) situated primarily in a vertical plane and forming a continuous 

 arc with the scapulocoracoids; (B) situated primarily in a horizontal plane and forming an 

 angle with the scapulocoracoids. 



65. Scapular fenestrae (Fig. 40): (A) large, invariably present; (B) small or absent. 



66. Posterior coracoid fenestrae (Fig. 40): (A) usually absent; (B) usually present. 



67. Clavicles: (A) wide, with a prominent lateral shelf; (B) narrow, the lateral shelf 

 small or absent. 



68. Posterior process of the interclavicle (Fig. 40): (A) extends posteriorly beyond the 

 lateral corners of the sternum; (B) does not extend beyond the lateral corners of the 

 stemum. 



69. Lateral processes of the interclavicle (Fig. 40): (A) usually forming angles of less 

 than 75° with the posterior process and giving the interclavicle the shape of an arrow; (B) 

 forming an angle of between 75° and 90° with the posterior process and giving the 

 interclavicle the shape of a T. 



70. Sternal fontanelle (Fig. 40): (A) present and of moderate size; (B) small or absent. 



71. Stemum-xiphistemum (Fig. 40): (A) sternum diamond-shaped (quadrilateral), the 

 xiphisterna in close proximity; (B) intermediate; (C) sternum pentagonal, the xiphisterna 

 widely separated. 



72. Pelvic girdle (Fig. 41): (A) long and narrow; (B) short and broad. 



