taxonID	type	description	language	source
9C298799D2465A3EFF2DFBB52405AE95.taxon	description	FRONTAL Frontals (Figs 2, 3) can be either paired or fused in a single element. This bone is more or less constricted in the middle, with the posterior end that is wider than the anterior one. The anterior end can have a medial process in the middle and lateral processes on the anterolateral corners, whereas the posterior end expands laterally forming the posterolateral processes. On the anterior margin, the articulation surfaces with the nasals are present on the dorsal side, whereas laterally one can see those with the facial process of the maxilla and the dorsal process of the prefrontals. The articulation surfaces with the postfrontal / postorbitofrontal can be present laterally near the posterior margin. Each lateral margin of the frontals develops in ventral direction forming a crista cranii that borders the olfactory lobes of the brain laterally. The anterior processes develop in anteroventral direction from the anterior end of each crista.	en	Villa, Andrea, Delfino, Massimo (2019): A comparative atlas of the skull osteology of European lizards (Reptilia: Squamata). Zoological Journal of the Linnean Society 187 (3): 828-928, DOI: 10.1093/zoolinnean/zlz035, URL: https://academic.oup.com/zoolinnean/article/187/3/829/5528353
9C298799D24A5A33FC95FAFD2412AC19.taxon	description	PARIETAL Parietals (Figs 5, 6) are quadrangular bones that can be either paired (only in gekkotans; Villa et al., 2018 a) or fused into a single element. They are composed of a straight parietal table that develops the anterolateral processes at the anterolateral corners and the supratemporal processes [postparietal processes in Evans (2008) and Villa et al. (2018 a)] at the posterolateral corners. The former are usually anterolaterally directed, whereas the latter are posterolaterally directed and ventrally curved. The table can be pierced by the parietal foramen.	en	Villa, Andrea, Delfino, Massimo (2019): A comparative atlas of the skull osteology of European lizards (Reptilia: Squamata). Zoological Journal of the Linnean Society 187 (3): 828-928, DOI: 10.1093/zoolinnean/zlz035, URL: https://academic.oup.com/zoolinnean/article/187/3/829/5528353
9C298799D24F5A34FC87FB9425FFABCE.taxon	description	PREMAXILLA The unpaired premaxilla (Figs 8, 9) is composed of a ventral alveolar plate and an ascending nasal process that projects posterodorsally from the middle portion of the alveolar plate. Posteriorly, the alveolar plate extends into the two thin and triangular palatal processes, divided medially by a wide notch. Between the bases of these processes, the small and ventrally directed incisive process is present. The teeth are supported by the alveolar margin of the alveolar plate. By the junction between the ascending nasal process and the alveolar plate, the foramina of the longitudinal canals are visible by the sides of the process. A septonasal crest runs medially along the posterior surface of the nasal process.	en	Villa, Andrea, Delfino, Massimo (2019): A comparative atlas of the skull osteology of European lizards (Reptilia: Squamata). Zoological Journal of the Linnean Society 187 (3): 828-928, DOI: 10.1093/zoolinnean/zlz035, URL: https://academic.oup.com/zoolinnean/article/187/3/829/5528353
9C298799D2535A28FC87FBE8230BA8C8.taxon	description	MAXILLA The paired maxillae (Figs 11, 12) consist of an alveolar portion and a dorsomedially developed facial process. The alveolar portion is composed by a tooth-bearing alveolar border and by a palatal shelf developed medially. The anterior end (anterior premaxillary process) has a concave anterior margin due to the presence of the anteromedial and anterolateral processes. The posterior end corresponds to an elongated posterior process. The maxilla is crossed by the superior alveolar canal, which runs through the base of the facial process. Its anterior opening, the vomeronasal foramen, is located on the dorsal surface of the premaxillary process. The posterior opening, on the other hand, is the wide superior dental foramen [infraorbital foramen in Barahona (1996)] and opens on the dorsal surface of the palatal shelf. Lateral openings of the canal are represented by the ventrolateral (labial) foramina, whose number is highly variable, even in the two maxillae of the same specimen.	en	Villa, Andrea, Delfino, Massimo (2019): A comparative atlas of the skull osteology of European lizards (Reptilia: Squamata). Zoological Journal of the Linnean Society 187 (3): 828-928, DOI: 10.1093/zoolinnean/zlz035, URL: https://academic.oup.com/zoolinnean/article/187/3/829/5528353
9C298799D2575A2CFC87FA252567ACA0.taxon	description	(MDHC 427), left maxilla in dorsal view. V, Anguis gr. An. fragilis (MDHC 102), left maxilla in dorsal view. Abbreviations: alp, anterolateral process; amp, anteromedial process; app, anterior premaxillary process; ar, arched ridge; l, lappet; ps, palatal shelf; sdf, superior dental foramen; vnf, vomeronasal foramen. Scale bars = 1 mm. and does not present steps. Except for Ophiomorus punctatissimus (Fig. 12 I, J), its posterior tip is slightly shifted in the dorsal direction (Fig. 12 C – H, K, L). The location of the small vomeronasal foramen is similar to the condition seen in lacertids, but in scincids the concavity is shallower because of the absence of a clearly developed lateral ridge. The medial ridge, on the other hand, is present but low in Chalcides ocellatus (Fig. 12 G, H) and Tr. aurata (Fig. 12 K, L), and well developed in Ab. kitaibelii (Fig. 12 C, D), Chalcides chalcides (Fig. 12 E, F), Chalcides striatus and Ophiomorus punctatissimus (Fig. 12 I, J). In the latter four species, the ridge continues on the dorsal surface of the anteromedial process in a distinct lappet. In Ophiomorus punctatissimus, the lappet bends strongly in the medial direction, giving a forked aspect to the anterior end of the anteromedial process in dorsal view (Fig. 12 U). The opening of the superior dental foramen is medially oriented. A moderately deep groove is present on the dorsal surface of the posterior process, posteriorly to the latter foramen, although it seems not to be in continuity with it (as it is, for example, in lacertids). As in the premaxillae, teeth are similar to those of gekkotans (Villa et al., 2018 a), but they have a slightly posterolingually curved crown provided with light striae on the lingual surface. Teeth are absent only on the tip of the posterior process. The ones of Chalcides ocellatus are robust and have a blunt and very enlarged crown (Fig. 12 G, H). Even if not as much as in Chalcides ocellatus, more robust teeth are present in Ophiomorus punctatissimus too (Fig. 12 I, J). In the latter species, the increase in robustness is less marked in the anteriormost teeth, but becomes more evident towards the posterior end of the tooth row. Anyway, the last tooth is slightly smaller than the preceding one. The facial process is roughly pentagonal in lateral view. The anterior and posterior margins are concave, whereas the anterodorsal and posterodorsal ones are roughly straight, although slightly irregular. Trachylepis aurata differs from the other species in having a strongly concave posterodorsal margin (Fig. 12 K, L). Ophiomorus punctatissimus does not display a clear distinction between an anterodorsal and a posterodorsal segment of the dorsal margin, which is rather convex in this species (Fig. 12 I, J). In Chalcides chalcides, Chalcides striatus and Tr. aurata, the dorsal margins are similar in length (Fig. 12 E, F, K, L), whereas in Ab. kitaibelii and Chalcides ocellatus the anterodorsal one is longer than the posterodorsal one (Fig. 12 C, D, G, H). In Ab. kitaibelii, this difference in length is very strongly marked, because the posterodorsal margin is less than one-third of the anterodorsal one (Fig. 12 C, D). The anterior, dorsal and posterior corners of the process are pointed in Chalcides (Fig. 12 E – H), but they do not develop projections. Trachylepis aurata shares a similar morphology, but the dorsal corner is rounded (Fig. 12 K, L), whereas all corners are rounded in Ab. kitaibelii and Ophiomorus punctatissimus (Fig. 12 C, D, I, J). The lateral surface is smooth, whereas a very low arched ridge is visible on the medial one. This latter ridge is similar to the one present in some lacertids, but much lower (almost not recognizable in Ab. kitaibelii, Chalcides ocellatus, Ophiomorus punctatissimus and Tr. aurata). The Supporting Information 4 includes measurements, number of tooth positions and number of ventrolateral foramina.	en	Villa, Andrea, Delfino, Massimo (2019): A comparative atlas of the skull osteology of European lizards (Reptilia: Squamata). Zoological Journal of the Linnean Society 187 (3): 828-928, DOI: 10.1093/zoolinnean/zlz035, URL: https://academic.oup.com/zoolinnean/article/187/3/829/5528353
9C298799D2545A2DFC95FDD02464AF8C.taxon	description	PREFRONTAL The paired prefrontal (Fig. 14) has an anteriorly concave body, named the orbitonasal flange. The large and pointed dorsal process starts from the medial side of the dorsal margin of the flange, extending in the posterodorsal direction. The laminar anterodorsal process develops in anterior direction from the orbitonasal flange and a posteroventral process develops ventrolaterally from its ventrolateral corner. A small posterolaterally directed projection is present at the tip of the posteroventral process. A wide notch of the lacrimal foramen is located between the anterodorsal and the posteroventral processes.	en	Villa, Andrea, Delfino, Massimo (2019): A comparative atlas of the skull osteology of European lizards (Reptilia: Squamata). Zoological Journal of the Linnean Society 187 (3): 828-928, DOI: 10.1093/zoolinnean/zlz035, URL: https://academic.oup.com/zoolinnean/article/187/3/829/5528353
9C298799D25B5A23FF1FFB7325C7AC57.taxon	description	JUGAL Jugals (Fig. 16) are curved and paired bones, roughly L-shaped in lateral view, with an anterior and a posterodorsal process. The anterior process can have a medially developed shelf, the palatal process, whose posterior end can develop a triangular medial process of the jugal. Between the anterior and the posterodorsal processes, a quadratojugal process can develop in ventral direction. A row of small foramina pierces the lateral surface of the bone.	en	Villa, Andrea, Delfino, Massimo (2019): A comparative atlas of the skull osteology of European lizards (Reptilia: Squamata). Zoological Journal of the Linnean Society 187 (3): 828-928, DOI: 10.1093/zoolinnean/zlz035, URL: https://academic.oup.com/zoolinnean/article/187/3/829/5528353
9C298799D2585A21FC95F92E2220AA2C.taxon	description	posterodorsal process is more robust and has a truncated (Chalcides chalcides, Chalcides striatus and Tr. aurata; Fig. 16 O, P), pointed (Chalcides bedriagai) or rounded (Ab. kitaibelii, Chalcides ocellatus and Ophiomorus punctatissimus; Fig. 16 M, N, Q, R) dorsal end. The length of the two processes is similar in Chalcides chalcides (Fig. 16 O, P), whereas in Chalcides ocellatus and Ophiomorus punctatissimus the posterodorsal	en	Villa, Andrea, Delfino, Massimo (2019): A comparative atlas of the skull osteology of European lizards (Reptilia: Squamata). Zoological Journal of the Linnean Society 187 (3): 828-928, DOI: 10.1093/zoolinnean/zlz035, URL: https://academic.oup.com/zoolinnean/article/187/3/829/5528353
9C298799D2595A21FC87FDD825EFAB9E.taxon	description	POSTFRONTAL AND POSTORBITAL Postfrontal and postorbital (Fig. 19) are paired bones that have a high variation in morphology throughout the groups of squamates here considered. They can be separate during the entire life of the animal, fuse during ontogeny or be present as a single element called postorbitofrontal. The latter can originate from early fusion of postfrontal and postorbital, but can also be the result of the loss of one of the two bones, as in many cases it is not known if such loss occurs and which bone remains (see, for example: Jollie, 1960; Evans, 2008; Daza & Bauer, 2010).	en	Villa, Andrea, Delfino, Massimo (2019): A comparative atlas of the skull osteology of European lizards (Reptilia: Squamata). Zoological Journal of the Linnean Society 187 (3): 828-928, DOI: 10.1093/zoolinnean/zlz035, URL: https://academic.oup.com/zoolinnean/article/187/3/829/5528353
9C298799D25F5A24FC87F9A32037AA3E.taxon	description	may be reduced or lacking. The postorbital is present in Chalcides and Ophiomorus punctatissimus, but it appears to be absent in Ab. kitaibelii and it has not been possible to find it in the studied specimens of Tr. aurata. Nevertheless, in the latter case, this may be also due to a loss during preparation rather than to an actual absence of the bone in this species. The postfrontal is Y-shaped, with a laminar body, two pointed (rounded in Ophiomorus punctatissimus; Fig. 19 W – X) processes on the anterior corners and a concave anterior margin (Fig. 19 Q – Z). In dorsal view, the body is slender and triangular in Ab. kitaibelii (Fig. 19 Q, R), slender and subrectangular in Chalcides chalcides, Chalcides striatus and Ophiomorus punctatissimus (Fig. 19 S, T, W, X), wider and laterally expanded in the posterior-half in Chalcides ocellatus (Fig. 19 U, V), and wider and provided with a moderately developed and pointed posterior projection on the posterolateral corner in Tr. aurata (Fig. 19 Y, Z). A similar projection is also present in Ophiomorus punctatissimus (Fig. 19 W, X). Both the dorsal and the ventral surfaces are smooth, but a variable number of foramina can pierce the laminar body of the bone. In Chalcides chalcides, the anterolateral process is moderately developed, similar in size and length to the anteromedial one and slightly curved posteriorly at its distal end (Fig. 19 S, T). The anteromedial process is also moderately developed, but it is straight. Chalcides ocellatus and Tr. aurata, on the other hand, have a moderately large and long anteromedial process, which is longer than the anterolateral one (Fig. 19 U, V, Y, Z). Moreover, in the latter species, both processes are straight. Ablepharus kitaibelii, Chalcides striatus and Ophiomorus punctatissimus also have a longer anteromedial process, but it is more slender (Fig. 19 Q, R, W, X). The medial margin of the bone is distinctly dorsoventrally enlarged, forming a concave articulation surface for the contact with both the frontal and parietal, whereas the lateral one has only a narrow articular surface housing the postorbital (or the posterodorsal process of the jugal, when the postorbital is absent). In Ab. kitaibelii, the concavity for the articulation with the frontal and parietal is very poorly developed and, therefore, the medial margin is not much expanded. The posterior end of the bone can be irregular because of a lower degree of ossification. The postorbital (Fig. 19 AA – AD) is an L-shaped and slender rod, with a short anterolateral process and a long posterior process. The distal end of both processes is pointed. In Chalcides ocellatus, this bone is more robust than in the other species (Fig. 19 AC – AD). The articulation surfaces with the postfrontal and the squamosal are recognizable in Chalcides ocellatus and Ophiomorus punctatissimus, on the medial side of the ventral surface and on the lateral side of the dorsal surface, respectively.	en	Villa, Andrea, Delfino, Massimo (2019): A comparative atlas of the skull osteology of European lizards (Reptilia: Squamata). Zoological Journal of the Linnean Society 187 (3): 828-928, DOI: 10.1093/zoolinnean/zlz035, URL: https://academic.oup.com/zoolinnean/article/187/3/829/5528353
9C298799D25C5A24FC95FF3F25D5AB36.taxon	description	SQUAMOSAL The squamosal (Fig. 20) is a paired and anteroposteriorly elongated bone. An anterior process forms the anterior end, whereas the posterior portion can be composed by a single posterior process or by a ventrally developed quadrate process and a posterodorsally developed dorsal parietal process. The morphology of this bone is highly variable between different groups.	en	Villa, Andrea, Delfino, Massimo (2019): A comparative atlas of the skull osteology of European lizards (Reptilia: Squamata). Zoological Journal of the Linnean Society 187 (3): 828-928, DOI: 10.1093/zoolinnean/zlz035, URL: https://academic.oup.com/zoolinnean/article/187/3/829/5528353
9C298799D2625A1AFF2DFF3F2399A922.taxon	description	QUADRATE The main body of the paired quadrate (Figs 21, 22) is a posteriorly curved pillar structure. From this pillar, an osseous lamina develops laterally forming a large and deep conch, which usually is strongly posteriorly concave. The lateral margin of the conch is defined by the slightly expanded tympanic crest. Another similar but much smaller lamina can be present on the medial side of the pillar, developing in the anteromedial direction. The pillar bears the dorsally flattened cephalic condyle dorsally and the mandibular condyle ventrally. The mandibular condyle is composed of two portions, which are separated by a concavity. Laterally to the cephalic condyle, a foramen for the chorda tympani nerve can be visible in dorsal view. In many cases this portion of the lateral lamina is poorly ossified and presents a more or less developed squamosal notch. One or two quadrate foramina may pierce the lateral lamina, dorsally to the mandibular condyle. However, the quadrate foramen can sometimes be absent.	en	Villa, Andrea, Delfino, Massimo (2019): A comparative atlas of the skull osteology of European lizards (Reptilia: Squamata). Zoological Journal of the Linnean Society 187 (3): 828-928, DOI: 10.1093/zoolinnean/zlz035, URL: https://academic.oup.com/zoolinnean/article/187/3/829/5528353
9C298799D2605A18FF2DFB9C2445AFDC.taxon	description	EPIPTERYGOID The epipterygoid (Fig. 23) is a rod-like paired bone.	en	Villa, Andrea, Delfino, Massimo (2019): A comparative atlas of the skull osteology of European lizards (Reptilia: Squamata). Zoological Journal of the Linnean Society 187 (3): 828-928, DOI: 10.1093/zoolinnean/zlz035, URL: https://academic.oup.com/zoolinnean/article/187/3/829/5528353
9C298799D2605A18FC95FA2324BAAA27.taxon	description	VOMERS T h e p a i r e d v o m e r s (F i g. 2 4) a r e l a m i n a r, anteroposteriorly elongated and dorsally concave. They are pointed anteriorly and wider posteriorly.	en	Villa, Andrea, Delfino, Massimo (2019): A comparative atlas of the skull osteology of European lizards (Reptilia: Squamata). Zoological Journal of the Linnean Society 187 (3): 828-928, DOI: 10.1093/zoolinnean/zlz035, URL: https://academic.oup.com/zoolinnean/article/187/3/829/5528353
9C298799D2615A19FC87FF3F2027AB15.taxon	description	The medial margin of the vomeronasal fenestra is marked by a lateral notch on the anterior-half of the bone.	en	Villa, Andrea, Delfino, Massimo (2019): A comparative atlas of the skull osteology of European lizards (Reptilia: Squamata). Zoological Journal of the Linnean Society 187 (3): 828-928, DOI: 10.1093/zoolinnean/zlz035, URL: https://academic.oup.com/zoolinnean/article/187/3/829/5528353
9C298799D2665A1FFC95F8F722A5AF67.taxon	description	SEPTOMAXILLA The septomaxilla (Fig. 25) is a small, laminar and paired bone, whose morphology varies in the different groups.	en	Villa, Andrea, Delfino, Massimo (2019): A comparative atlas of the skull osteology of European lizards (Reptilia: Squamata). Zoological Journal of the Linnean Society 187 (3): 828-928, DOI: 10.1093/zoolinnean/zlz035, URL: https://academic.oup.com/zoolinnean/article/187/3/829/5528353
9C298799D2645A1CFF2DF9ED2508AE0F.taxon	description	PALATINE The paired palatine (Fig. 26) is an anteroposteriorly elongated bone composed of three processes: the vomerine, maxillary and pterygoid processes, developed in anterior, lateral and posterior directions, respectively. The pterygoid process is always the longest one. On the dorsal surface of the bone, a palatine ridge runs transversely between the vomerine and maxillary processes, separating them, whereas the ventral surface of the palatine is characterized by the presence of the choanal duct. The maxillary process is pierced by the wide infraorbital foramen. Palatine teeth can be present on the ventral surface of the pterygoid process.	en	Villa, Andrea, Delfino, Massimo (2019): A comparative atlas of the skull osteology of European lizards (Reptilia: Squamata). Zoological Journal of the Linnean Society 187 (3): 828-928, DOI: 10.1093/zoolinnean/zlz035, URL: https://academic.oup.com/zoolinnean/article/187/3/829/5528353
9C298799D26A5A13FC95FEC82083AC78.taxon	description	PTERYGOID The paired pterygoid (Figs 27, 28) is composed of three branches: the anteromedial palatine process, the anterolateral pterygoid flange and the posterior quadrate process. Anteriorly, the pterygoid recess separates the palatine process and the pterygoid flange. The palatine process is laminar, but strengthens towards the medial margin. The pterygoid flange is usually pointed and slender, and bears two ridges that run along its dorsal and ventral surfaces. These ridges represent the insertion points of the superficial pseudotemporal muscle and of the pterigomandibular muscle, respectively (Barahona, 1996). The quadrate process is characterized by the presence of the subcircular fossa columellae on the dorsal surface and of the basipterygoid fossa on the medial one. Posterior to the former, a pterygoid ridge runs along the dorsolateral surface of the bone, whereas the basipterygoid fossa continues posteriorly in a concave surface for the insertion of the pterygoideus muscle. Pterygoid teeth can be present on the ventral surface of the palatine process.	en	Villa, Andrea, Delfino, Massimo (2019): A comparative atlas of the skull osteology of European lizards (Reptilia: Squamata). Zoological Journal of the Linnean Society 187 (3): 828-928, DOI: 10.1093/zoolinnean/zlz035, URL: https://academic.oup.com/zoolinnean/article/187/3/829/5528353
9C298799D26E5A16FF2DFBE022CCAC70.taxon	description	ECTOPTERYGOID The ectopterygoid (Fig. 29) is a small and paired bone, the morphology of which varies greatly among different groups.	en	Villa, Andrea, Delfino, Massimo (2019): A comparative atlas of the skull osteology of European lizards (Reptilia: Squamata). Zoological Journal of the Linnean Society 187 (3): 828-928, DOI: 10.1093/zoolinnean/zlz035, URL: https://academic.oup.com/zoolinnean/article/187/3/829/5528353
9C298799D26C5A14FF2DFCE725C8ACA0.taxon	description	GENERAL FEATURES OF THE BRAINCASE The sphenoid, the basioccipital, the prootics, the supraoccipital and the otooccipitals fuse together to form the braincase (Figs 30, 31, 32, 33, 34). The fusion is generally linked to ontogeny, with separated bones in juveniles that fuse in older individuals. On the posterior side of the region, the foramen magnum is defined by the basioccipital ventrally, the supraoccipital dorsally and the otooccipitals laterally. The otooccipitals and the basioccipital form the occipital condyle. On each side, the recessus scalae tympani is enclosed by the basioccipital and each otooccipital. The recessus opens externally with a ventrolaterally directed lateral opening and internally with a medial opening into the cranial cavity and a dorsomedial opening (the perilymphatic foramen) into the cochlear cavity. The external opening of the cochlear cavity is the wide fenestra ovalis, located between the prootics and otooccipitals. The paired anterior, horizontal and posterior semicircular canals are present on each side of the ossified braincase. The anterior canal passes through the prootic and the supraoccipital, the horizontal canal goes from the dorsal portion of the prootic to the base of the paraoccipital process of the otooccipital, and the posterior canal develops between the supraoccipital and the otooccipital.	en	Villa, Andrea, Delfino, Massimo (2019): A comparative atlas of the skull osteology of European lizards (Reptilia: Squamata). Zoological Journal of the Linnean Society 187 (3): 828-928, DOI: 10.1093/zoolinnean/zlz035, URL: https://academic.oup.com/zoolinnean/article/187/3/829/5528353
9C298799D2705A09FF2DF93520CAAA12.taxon	description	BASIOCCIPITAL The basioccipital (Fig. 36) is unpaired, subhexagonal and roughly as long as wide. It has a dorsally concave body, with a central cranial depression and two moderately developed lateral wings. In dorsal view, it has a roughly straight or concave anterior margin. Posteriorly, it forms the medial portion of the occipital condyle. The ends of the lateral wings develop the sphenooccipital tubercles and constitute the ventral wall of the recessus scalae tympani. The crista tuberalis marks the posterior wall of the recessus. The basioccipital is smooth, both dorsally and ventrally. The bones that fuse with this bone are the sphenoid anteriorly, the prootics anterolaterally and the otooccipitals posterolaterally.	en	Villa, Andrea, Delfino, Massimo (2019): A comparative atlas of the skull osteology of European lizards (Reptilia: Squamata). Zoological Journal of the Linnean Society 187 (3): 828-928, DOI: 10.1093/zoolinnean/zlz035, URL: https://academic.oup.com/zoolinnean/article/187/3/829/5528353
9C298799D2765A0FFC95FDCB2096A9BA.taxon	description	SPHENOID The complete fusion of parasphenoid and basisphenoid results in an unpaired sphenoid (Fig. 37). This bone has a roughly quadrangular body, from which two basipterygoid processes develop anterolaterally from the anterolateral corners. Two posterolaterally directed cristae ventrolaterales [parasphenoid wings in Daza et al. (2008)] can be also present at the posterolateral corners. On the dorsal surface of the body of the bone, there are two cylindrical trabeculae cranii, the sella turcica (including the hypophysial fossa) and the transverse crista sellaris. The trabeculae, located between the basipterygoid processes, are continued posteriorly by two low cristae trabeculares that border the sella turcica laterally. A parasphenoid rostrum [cultriform process in Daza et al. (2008)] can be present between the trabeculae, on the anterior margin of the bone. The crista sellaris composes the posterior margin of the sella turcica and contacts the prootics laterally, with the alar processes. The crista can develop anterodorsally to form a dorsum sellae that covers the sella turcica. Moreover, it is pierced anteroposteriorly by two abducens foramina. The dorsal surface of the posterior portion of the sphenoid, located posteriorly to the crista sellaris, is smooth. Ventrally, the sphenoid can have a sunken area in the middle. The Vidian canals open anteriorly medial to the base of the basipterygoid process, medially in the sella turcica (with the internal carotid foramina) and posterolaterally towards the contact with the prootics. Both sides of the sphenoid display the recessus vena jugularis extending in a posterodorsal direction, starting from the latter openings. The recessus continues on the prootics. The sphenoid contacts the basioccipital posteriorly and the prootics posterolaterally.	en	Villa, Andrea, Delfino, Massimo (2019): A comparative atlas of the skull osteology of European lizards (Reptilia: Squamata). Zoological Journal of the Linnean Society 187 (3): 828-928, DOI: 10.1093/zoolinnean/zlz035, URL: https://academic.oup.com/zoolinnean/article/187/3/829/5528353
9C298799D2765A0EFC95FF3F23C0A866.taxon	description	occipital condyle. The sphenooccipital tubercles are well developed and strongly built. They are roughly rounded and moderately narrow in lateral view. The development of the tubercles is weaker in juveniles.	en	Villa, Andrea, Delfino, Massimo (2019): A comparative atlas of the skull osteology of European lizards (Reptilia: Squamata). Zoological Journal of the Linnean Society 187 (3): 828-928, DOI: 10.1093/zoolinnean/zlz035, URL: https://academic.oup.com/zoolinnean/article/187/3/829/5528353
9C298799D2755A02FC87F9C02363AA0D.taxon	description	SUPRAOCCIPITAL The unpaired supraoccipital (Fig. 38) includes the epiotic of Jollie (1960). This bone is elongated transversely and posteriorly inclined. It can be separated into three portions: a thin medial portion and two wide lateral portions. The latter form the roof of each cavum capsularis. Posteriorly the supraoccipital represents the dorsal margin of the foramen magnum. Anteriorly, it can carry an anterodorsally developed processus ascendens or other different structures. The anterior margin of the bone hosts the dorsal portions of the anterior semicircular canals. The dorsal portions of the posterior semicircular canals run from the posterolateral corners to the middle of the dorsal surface of the bone. Anterior and posterior canals merge in the common crus, which in turn opens to the cavum capsularis. The endolymphatic foramina are present near the contact with the prootic, on the medial surface of each lateral portion of the supraoccipital. This foramina opens posterodorsally and are moderately wide. The supraoccipital is fused with the prootics and the otooccipitals.	en	Villa, Andrea, Delfino, Massimo (2019): A comparative atlas of the skull osteology of European lizards (Reptilia: Squamata). Zoological Journal of the Linnean Society 187 (3): 828-928, DOI: 10.1093/zoolinnean/zlz035, URL: https://academic.oup.com/zoolinnean/article/187/3/829/5528353
9C298799D27B5A01FC87FA012322AF25.taxon	description	PROOTIC The paired prootic (Fig. 40) includes a posterior process (posteriorly), an alar process (anterodorsally) and an anterior inferior process (ventrally). The horizontal semicircular canal and, anterodorsally to the latter, the anterior semicircular canal occupy the posterior process. Posteriorly, this process develops a projection that extends to cover the anterior surface of the paroccipital process of the otooccipital. The alar process extends from the anterodorsal end of the anterior semicircular canal, bearing the articulation surface with the epipterygoid on its anterior margin, which is named crista alaris. The anterior inferior process displays the incisura prootica, the facial foramen and the laminar crista prootica. The incisura prootica is broad and located medioventrally to the alar process. The facial foramen opens both to the lateral and medial surfaces, and ventrally to the horizontal semicircular canal and the crista prootica. The crista prootica runs anteroventrally, starting from the ventral end of the anterior semicircular canal. It continues also on the posterior process, curving posteriorly and becoming a ridge that runs ventrally to the horizontal semicircular canal. The posterior portion of the recessus vena jugularis runs ventrally to the crista prootica. Two other large foramina are visible medially, opening in a concave acoustic recess. These foramina are the smaller anterior acoustic foramen and the very large posterior acoustic foramen. The former is located dorsally to the facial foramen and opens in the ampullary recess, whereas the latter is placed slightly posteriorly and opens internally between the cochlear cavity and the cavum capsularis. These two foramina carry the branches of the vestibulocochlear nerve. The prootic encloses the anterior portion of the inner ear. Its inner structures include the anterior portions of the cavum capsularis dorsally, that of the cochlear cavity ventrally and the cochlear crest between them. The opening of the anterior semicircular canal flanks dorsally the cavum capsularis, whereas laterally to the latter there is the opening of the horizontal semicircular canal. The opening of the ampullary recess is visible at the medioventral corner of the cavum. The dorsal-half of the anterior wall of the cochlear cavity houses the wide groove for the perilymphatic duct. The prootic fuses with the sphenoid anteroventrally, the basioccipital posteroventrally, the supraoccipital posterodorsally and the otooccipital posteriorly.	en	Villa, Andrea, Delfino, Massimo (2019): A comparative atlas of the skull osteology of European lizards (Reptilia: Squamata). Zoological Journal of the Linnean Society 187 (3): 828-928, DOI: 10.1093/zoolinnean/zlz035, URL: https://academic.oup.com/zoolinnean/article/187/3/829/5528353
9C298799D27E5A06FF2DFEC82571AC3B.taxon	description	OTOOCCIPITAL The otooccipital (Fig. 41) is a paired bone made up by the complete fusion of exoccipital and opisthotic, which are not recognizable as separate elements. Each otooccipital takes part in composing the occipital condyle. The posterior semicircular canal is visible on the posterior surface of the bone, running vertically and continuing dorsally on the supraoccipital. Few foramina are located between the ventral end of the posterior semicircular canal and the occipital condyle. The vagus foramen is the largest and most dorsally located of these foramina. The other ones are the hypoglossal foramina, whose number is highly variable. On the lateral side of the otooccipital is the well-developed paroccipital process that is roughly rectangular in posterior view. The posterior portion of the horizontal semicircular canal is visible by the base of this process. The crista interfenestralis marks the dorsal margin of the lateral opening of the recessus scalae tympani, running anteroventrally from the paroccipital process on the lateral surface of the otooccipital. The posterior portion of the inner ear is enclosed by this bone. It houses the posterior walls of the cavum capsularis and of the cochlear cavity, located dorsally and ventrally, respectively. There are no ridges or grooves separating the two cavities, but the openings of the ampullary recess ventrally and of the utricular recess dorsally are visible inside the cavum capsularis. The openings of the horizontal semicircular canal and the posterior semicircular canal are present laterally and dorsally to the cavum, respectively. Inside the cochlear cavity is the perilymphatic foramen, opening in the recessus scalae tympani. The otooccipital contacts the basioccipital ventrally, the prootic anteriorly and the supraoccipital dorsally, fusing with them.	en	Villa, Andrea, Delfino, Massimo (2019): A comparative atlas of the skull osteology of European lizards (Reptilia: Squamata). Zoological Journal of the Linnean Society 187 (3): 828-928, DOI: 10.1093/zoolinnean/zlz035, URL: https://academic.oup.com/zoolinnean/article/187/3/829/5528353
9C298799D27F5A04FC87FAB223EBACDC.taxon	description	STAPES The paired stapes (Fig. 42) is a small bone composed of a slender shaft and an enlarged medial footplate.	en	Villa, Andrea, Delfino, Massimo (2019): A comparative atlas of the skull osteology of European lizards (Reptilia: Squamata). Zoological Journal of the Linnean Society 187 (3): 828-928, DOI: 10.1093/zoolinnean/zlz035, URL: https://academic.oup.com/zoolinnean/article/187/3/829/5528353
9C298799D27C5A04FF2DFBC52544ABD5.taxon	description	DENTARY The dentary (Fig. 43) is a long, paired bone. It is straight in both dorsal and medial views, but the anterior end bends moderately in the medial direction. The mandibular symphysis covers the medial surface of the anterior end. The Meckelian fossa stands out on the medial surface of the bone, housing the anterior portion of the Meckel’s cartilage. Dorsally to the fossa, there is an alveolar shelf [parapet in Rage & Augé (2010)] supporting the teeth. The bony structures separating the Meckelian fossa from the alveolar shelf were differently named by different authors in the past [including the authors of the present paper; see, for example: Villa et al. (2018 a, b)], generating a certain degree of ambiguity on how to correctly define some terms. We herein follow the terminology proposed by Rage & Augé (2010), updating it with a single addition (the subdental ridge; see below). We choose this terminology because it gives clear definitions of the terms used. Teeth are supported ventrally by a subdental table. This table more or less extends medially to form a subdental shelf that is not covered dorsally by the tooth bases. Dorsally, the subdental shelf can have a subdental ridge, which marks the medial margin of the sulcus dentalis. The alveolar canal is present between the Meckelian fossa and the subdental table, housing the inferior alveolar nerve. This canal is visible only as a foramen opening in the posterior direction, since the intramandibular septum closes it medioventrally. The inferior posterior process and the superior posterior process develop at the posterior end of the dentary. They are laminar and posteriorly directed. The lateral surface of the dentary is smooth in extant European lizards, except for a variable number of anteroposteriorly aligned mental foramina. Before describing the dentaries of the different lizard groups herein considered, we briefly revise the descriptions of the groups treated by Villa et al. (2018 a, b), using a terminology different to those of Rage & Augé (2010). In gekkotans, the subdental table strongly develops medially to form a subdental shelf that is extensively expanded ventrally and contributes to the enclosure of the Meckelian fossa. Dorsally, a distinct subdental ridge and the related sulcus dentalis are visible. In Blanus, the subdental shelf is rather high in medial view, but not strongly extended in the medial direction. Posteriorly, the subdental shelf displays a wide V-shaped notch in medial view. A low subdental ridge and a shallow sulcus dentalis are present dorsally. The reader is still referred to the original papers for the rest of the description of the dentary in these two groups.	en	Villa, Andrea, Delfino, Massimo (2019): A comparative atlas of the skull osteology of European lizards (Reptilia: Squamata). Zoological Journal of the Linnean Society 187 (3): 828-928, DOI: 10.1093/zoolinnean/zlz035, URL: https://academic.oup.com/zoolinnean/article/187/3/829/5528353
9C298799D2035A78FF1FF96C22C2AF41.taxon	description	SPLENIAL The paired splenial (Fig. 45) is a blade-like bone, pierced by two foramina: the anterior inferior foramen anterodorsally and the anterior mylohyoid foramen posteroventrally.	en	Villa, Andrea, Delfino, Massimo (2019): A comparative atlas of the skull osteology of European lizards (Reptilia: Squamata). Zoological Journal of the Linnean Society 187 (3): 828-928, DOI: 10.1093/zoolinnean/zlz035, URL: https://academic.oup.com/zoolinnean/article/187/3/829/5528353
9C298799D2015A79FC87FDBC2448AB98.taxon	description	CORONOID The paired coronoid (Fig. 47) is composed of five processes. The dorsally developed and subtriangular coronoid process stands out in the middle of the bone. Adding to this process, there are the labial process anterolaterally, the anteromedial process anteromedially, the posterior process posteriorly and the posteromedial process posteromedially. The anteromedial process is always larger and longer than the labial process and both are pointed. The morphology of other processes varies among different groups.	en	Villa, Andrea, Delfino, Massimo (2019): A comparative atlas of the skull osteology of European lizards (Reptilia: Squamata). Zoological Journal of the Linnean Society 187 (3): 828-928, DOI: 10.1093/zoolinnean/zlz035, URL: https://academic.oup.com/zoolinnean/article/187/3/829/5528353
9C298799D2075A7FFF1FFD0425D4AF64.taxon	description	can display a small posterior process in some specimen (e. g. MCZ 38517). A well-developed coronoid ridge connects the dorsal end of the coronoid process with the ventral end of the posteromedial process, running along the posterior margin of the former and the anterior margin of the latter. In the smallest species (e. g. Chalcides chalcides), the ridge is similar to the osseous lamina found in gekkotans (Villa et al., 2018 a). In Chalcides ocellatus, similarly to lacertids, a second, low ridge runs on the posterior surface of the coronoid process, continuing posteriorly on the dorsal portion of the posteromedial process (Fig. 47 K, L).	en	Villa, Andrea, Delfino, Massimo (2019): A comparative atlas of the skull osteology of European lizards (Reptilia: Squamata). Zoological Journal of the Linnean Society 187 (3): 828-928, DOI: 10.1093/zoolinnean/zlz035, URL: https://academic.oup.com/zoolinnean/article/187/3/829/5528353
9C298799D2075A7CFC87FD9F25DFAF89.taxon	description	ANGULAR, SURANGULAR, PREARTICULAR AND ARTICULAR These four bones (Figs 49, 50, 51) compose the posterior portion of the mandible, enclosing the posterior portion of the Meckel’s cartilage. They can fuse completely or partially to form a compound bone. The angular is a laminar and elongated bone, composing the ventrolateral wall of this portion of the mandible. The elongate surangular is located dorsally and contributes to the formation of the dorsal and lateral walls of the mandible. At the middle of its length it is expanded and displays a slightly irregular and sunken dorsomedial surface. Another laminar expansion is present near the posterior end. This second expansion is arched and encircles the articular condyle of the articular. Two foramina can be seen in lateral view: the anterior surangular foramen and the posterior surangular foramen. The former is located near the dorsal margin of the bone at the anterior expanded area, whereas the latter is placed near the ventral margin at the posterior expansion. The prearticular and the articular are always fused in a single and straight bone composing the ventral wall of the mandible. This bone has a pointed anterior end and expands dorsally by the second-fourth of its length, forming a projection that contacts the surangular. The posterior end of the bone presents the articular condyle with the quadrate dorsally and the retroarticular process posteriorly. The condyle is wide and subcircular or subquadrangular; the articulation surface is directed posteromedially and bears two slightly sunken areas separated by a low median ridge. The retroarticular process is usually long and wide. It is dorsomedially concave and bears a foramen for the chorda tympani near the anteroventral corner of the medial surface. An angular process can develop in the medial direction ventrally to the condyle. Medially, the broad adductor fossa is present anteriorly to the articular condyle. The fossa is defined by the surangular dorsally and by the prearticular / articular complex ventrally.	en	Villa, Andrea, Delfino, Massimo (2019): A comparative atlas of the skull osteology of European lizards (Reptilia: Squamata). Zoological Journal of the Linnean Society 187 (3): 828-928, DOI: 10.1093/zoolinnean/zlz035, URL: https://academic.oup.com/zoolinnean/article/187/3/829/5528353
