Oardasaurus glyphis, Codrea & Venczel & Solomon, 2017

Codrea, Vlad A., Venczel, Márton & Solomon, Alexandru, 2017, A new family of teiioid lizards from the Upper Cretaceous of Romania with notes on the evolutionary history of early teiioids, Zoological Journal of the Linnean Society 181, pp. 385-399 : 389-396

OARDASAURUS GLYPHIS SP. NOV.

( FIGS. 2C, D, 3A–K, 4A–K, 5A–G)

Holotype: PSMUBB.ODAN-A-12 ( Fig. 2C, D, 3A–C), incomplete parietal from the uppermost Cretaceous ODA locality, southwestern Transylvania, Romania.

Diagnosis: Small- to middle-sized Late Cretaceous teiioid lizard with an estimated total body length up to 200 mm. The holotype parietal resembles that of Barbatteius , but differs from all the other lizards, by the following unique combination of features: temporal muscles originate dorsally on the lateral (i.e. descending) flanges of the parietal and on the supratemporal processes; the upper temporal fenestra is not occluded by either the postorbital or postfrontal; extensive osteodermal sculpture covers and strongly fuses to the parietal and to the anterior part of supratemporal processes. It further resembles Barbatteius and the possible teiioid Meyasaurus (Early Cretaceous, Spain), but differs from all the other teiioids in bearing the impressions of the cephalic scales on the outer surface of the osteodermal sculpture. It differs from Barbatteius by its smaller size, and from both Barbatteius and Meyasaurus in the pattern of osteodermal sculpture that consists of deep pits and crests, and in having the occipital scute divided in two or three smaller osteoscutes.

L o c a l i t y a n d h o r i z o n: U p p e r m o s t C r e t a c e o u s (Maastrichtian) Oarda de Jos A locality, southwestern Transylvania, Romania.

Etymology: From Greek ‘glyphe’, meaning carving.

Description of holotype: The anterior part of the parietal, the right supratemporal process and the distal part of the left supratemporal process are missing. In dorsal or ventral views, the parietal is elongate and shallowly constricted at the level of the parietal foramen, whereas the anterior and posterior parts are somewhat widened. The dorsal surface of the parietal table is covered by a thick osteodermal crust divided by deep and wide furrows running anteroposteriorly, mediolaterally or obliquely ( Fig. 3A). The osteoscutes are ornamented by irregularly distributed pits, ridges, tubercles and fossae. The occipital scute is divided by deep grooves in three small scutes (one anterior and two posterior ones) depicting collectively a more or less pentagonal outline. Anterior to the occipital scutes there is a small transitional scute of triangle shape, delimited by two anteriorly divergent (i.e. ‘V-shaped’) grooves and a transversal anterior furrow. The interparietal scute, with its anterior margin broken away, encloses a large parietal foramen. The latter is surrounded by a sharp circular crest, interrupted irregularly by pits and foramina, and circumscribed by a deep furrow. The parietal scutes are elongate and moderately wide, but narrowed to ridge-like structures at the level of the parietal foramen; anterior to that point they are widening again. On the other hand, the parietal scutes are divided by three pairs of irregular and mediolaterally trending grooves at the levels of the parietal foramen, the transitional scute and the occipital scutes. Nevertheless, these grooves are shallower than those situated on the medial part of the parietal table. Posterior to the left parietal scute, there is a small supratemporal scute preserved, delimited by a shallow transversal groove ( Fig. 3A). The lateral borders of the parietal are almost vertical, or even deflected ventromedially at their dorsal parts and splayed ventrolaterally at their ventral parts, exposing elongate and deep supratemporal fossae. This morphology indicates that in the living animal the jaw adductor musculature invaded the dorsal parts up to the sculpted surface ( Fig. 3C). The supratemporal processes diverged posterolaterally almost at a right angle. The nearly completely preserved left supratemporal process is mediolaterally compressed, bent downward and of moderate length. In ventral view, the recessus processi ascendentis (=‘parietal fossa’ of Oelrich, 1956) is situated at about half of the distance between the parietal foramen and the posterior margin of the parietal ( Fig. 3B). The recess flares posteriorly into a large embayment (i.e. parietal notch), bordered laterally by the medially convex walls of cristae juxtafovealis. At the anterolateral parts of the parietal notch, the cristae juxtafovealis develop into ventrally pointed processes; however, both missing their tips. In the living animal these processes articulate with the alar processes of the prootics. Two elongated and posteriorly deepening fossae, delimited medially by the cristae juxtafovealis, develop on both sides of recessus processi ascendentis. Each fossa is intersected by a faint ridge that connects the ventral process of crista juxtafovealis and the posterior ramus of crista cranii parietalis. Anterolaterally to the recessus processi ascendentis the cristae juxtafovealis merge into low-arched convexities directed to the lateral margins. The ventral surface between these convexities remains smooth, but slightly inflects into the parietal foramen. Posterior to the parietal foramen there is a shallow notch of unknown function. The posterior ramus of crista cranii parietalis, similarly to Barbatteius , runs along the lateral margin of the supratemporal process ( Venczel & Codrea, 2016; Fig. 2B).

Description of the referred material

Parietal: The specimen PSMUBB.ODAN-A-13 ( Fig. 3D–G), reported earlier by Jipa (2012: pl. 8: 3a, b) as Lacertilia indet. (‘Lizard 3’), represents an incomplete parietal with the anterior margin of the parietal table and distal parts of the supratemporal processes broken away. After removal of sediment cover ( Fig. 3E), a dorsal sculpture similar to that of the holotype was exposed. The posterior margin of the parietal table appears asymmetrical with the occipital embayment shifted to the left. The occipital scute is divided into two small osteoscutes, the left being somewhat smaller. As in the holotype, the parietal scutes are divided by irregular and mediolaterally directed grooves. The transitional scute is also triangular with its apex angle pointing posteriorly. In ventral view, the cristae juxtafovealis develop into bulging ventrally pointed processes ( Fig. 3D). The concavities bordered by the cristae juxtafovealis and the posterior rami of cristae cranii parietalis are comparatively deeper than those in the holotype.

The specimen PSMUBB.ODAN-A-14 is a small fragment from the parietal table. In dorsal view, it resembles the holotype and PSMUBB.ODAN-A- 13 in having an interparietal scute circumscribed by a deep furrow and in possessing a small transitional scute. However, contrary to the above specimens, the transitional scute is divided by a longitudinal groove .

Comparisons: The parietal in Oardasaurus , similarly to Barbatteius , is covered by a thick osteodermal sculpture displaying the impressions of cephalic scales, termed as pileus by Friederich (1978). The fusion line between the parietal table and the cephalic osteoderms is exposed on the lateral and posterior margins of the parietal ( Fig. 3C, G). The skull roof in Recent teiids occasionally bears an attenuated osteodermal crust (e.g. Ameiva , Cnemidophorus and Kentropyx ), but in most members it is devoid of such cover ( Estes, 1983). In Aspidoscelis , Teius and Tupinambis the dorsal surface of the parietal bears a network of shallow grooves and pits, whereas in Dracaena it remains smooth (see also Venczel & Codrea, 2016). Conversely, in Callopistes the parietal table is reduced to a median crest and the jaw adductor musculature invades up to the midline of the bone. The impressions left by the cephalic scales on the skull roofing bones (i.e. the pileus pattern) appear quite constant within the crown lacertids demonstrating a strict ontogenetic control and it is considered a synapomorphy of that group ( Borsuk-Białynicka et al., 1999). Conversely, a variable pileus pattern appears in teiids (e.g. see Harvey et al., 2012) that may represent the plesiomorphic condition ( Borsuk-Białynicka et al., 1999). In the possible crown lacertids Succinilacerta Böhme & Weitschat, 1998 , known from the middle Eocene Baltic amber of Poland and Lithuania ( Borsuk-Białynicka et al., 1999) and in Plesiolacerta lydekkeri Hoffstetter, 1942 , known from the middle Eocene-early Oligocene (MP14-MP21) of France (Čerňanský & Augé, 2013), the occipital scute is placed medially and strongly widens posteriorly. The reconstructed pileus of Meyasaurus unaensis Richter, 1994 exhibits a single and posteriorly widening occipital scute ( Richter, 1994; Borsuk-Białynicka et al., 1999), whereas those of Plesiolacerta eratosthenesi Čerňanský & Augé, 2013 and Barbatteius vremiri remain narrow and are of rectangular (Čerňanský & Augé, 2013) or pentagonal outline ( Venczel & Codrea, 2016), respectively. In Oardasaurus glyphis the occipital scute is divided into two or three smaller osteoscutes, whereas the elongated parietal scutes are also subdivided by shallow transversal grooves. The variable pileus pattern in Barbatteiidae (i.e. undivided occipital scute in Barbatteius vs. variable number of occipital scutes in Oardasaurus ) may represent an intermediate condition between teiids and lacertids.

Postorbital: The specimen PSMUBB.ODAN-A-18 ( Fig. 3H–K) is dorsoventrally flattened and the anterior part of a postorbital is preserved; the posteriormost part (i.e. the squamosal process), which in the living animal covers the squamosal dorsally, is broken away. The dorsal sculpture is reminiscent of the other available skull roofing bones of Oardasaurus consisting of ridges, pits and grooves ( Fig. 3H). Two small osteoscutes are situated on the anterodorsal part of the postorbital, whereas the remaining dorsal surface is covered by a larger osteoscute delimited anteriorly and laterally by deep pits and low ridges. The anteromedial part, which in the living animal is probably articulated or fused completely with the postfrontal, is broken away ( Fig. 3H, I, K). The medial margin, which borders laterally the upper temporal fenestra, is smooth and without any trace of suture ( Fig. 3K). In lateral view, the anterolateral part displays the distally incomplete jugal process that delimits posteriorly a deep, concave surface marking the articulation point with the jugal’s dorsal arm ( Fig. 3J). In ventral view, the bone is shallowly concave and has a low longitudinal ridge near its medial margin ( Fig. 3I).

Comparisons: Assignment of PSMUBB.ODAN-A-18 to Oardasaurus glyphis is supported by a similar dorsal osteodermal crust seen in the holotype, and by the morphology of its medial margin. The smooth medial margin of the postorbital (i.e. without a sutural articulating surface to either the postfrontal or the parietal) demonstrates that the upper temporal fenestra was not occluded by either the postfrontal or the postorbital. Similarly to Oardasaurus , the postorbital of Barbatteius was also covered by several osteoscutes, delimited by deep grooves ( Venczel & Codrea, 2016). Conversely, in Meyasaurus, Polyglyphanodontia and Recent teiids, taxa possessing unoccluded upper temporal fenestrae, the postorbitals are free of such osteodermal crust.

Frontal: Apart from the wide range of ontogenetic variations (i.e. the largest specimen is twice the size of the smallest one), the referred specimens share several comparable features as follows: the frontals are completely fused; the frontal–parietal sutural surface is more or less straight and has a serrated margin; the imprint left by the postfrontal anterior arm on the lateral side has the same anterior extent; the osteodermal islets are almost similarly distributed on the dorsal surface and the imprints left by the parietal tabs are present. Nevertheless, the larger specimens possess a taller osteodermal sculpture, more widened posterior margins of the fused frontals and markedly concave orbital margins. The largest specimen is PSMUBB.ODAN-A-15 ( Fig. 4A–C), mentioned by Jipa (2012: pl. 8: 5, in ventral view) as ‘ODAN-Lizard 4’, in which the posterior part of a fused frontal is preserved. The dorsal surface displays numerous pits and a network of anteroposteriorly trending deep furrows delimiting crests and tubercles ( Fig. 4A). Frequently, the dorsal margins of these crests coalesce into more extensive lamellar islets. Medially, alongside the cracks, these emerged structures are broken away. The bone is steeply constricted between the orbits, whereas the nearly intact and flaring posterior margin displays a serrated articulation surface for the parietal. The sutural surface is nearly straight medially, whereas the lateral parts have distinct posterior projections. In ventral view, posterior to crista cranii frontalis, bilateral impressions of roughly triangular shape reveal the existence of the parietal tabs. In lateral view, the imprint left by the anterior arm of the postfrontal is relatively long. In PSMUBB.ODAN-A-16 ( Fig. 4G, K), the right posterolateral part of a fused frontal is preserved, whereas the posterior margin is damaged medially. The posterior projection is well-preserved and the impression left by the parietal tab is also present. PSMUBB.ODAN-A-17 represents an incomplete fused frontal with its anterior and left posterior parts broken away ( Fig. 4D–F). The specimen appears to be closely similar in morphology and size to PSMUBB. ODAN-A-16; however, both are smaller and have a more attenuated dorsal sculpture than PSMUBB. ODAN-A-15. PSMUBB.ODAN-A-23 is the smallest specimen referred to Oardasaurus ( Fig. 4H–J) and consists of a complete posterior half of a fused frontal. It is reminiscent of the other specimens in possessing a similar outer sculpture, a straight fronto-parietal sutural line and in possessing the imprints left by the parietal tabs and those of the postfrontals. Nevertheless, its outer sculpture is more diminutive and its posterior part less widened when compared to the remaining specimens.

Comparisons: The frontals in all the referred specimens of Oardasaurus , similarly to Barbatteius, Gekkota , Carusiidae , Lygosominae and Xenosauridae (see Gauthier et al., 2012), are fused completely. Within the clade of Laterata, the frontals are paired in amphisbaenians ( Estes et al., 1988), are of variable condition in lacertids (i.e. paired or fused; Bolet & Evans, 2012, Čerňanský & Augé, 2013), whereas in Recent teiids and gymnophthalmids they are always fused. The teiid-like polyglyphanodontians, in all taxa for which it can be evaluated, retain the paired condition well into the postembryonic ontogeny ( Sulimski, 1975; Estes et al., 1988). The same holds true for Pedrerasaurus Bolet & Evans, 2010 (Early Cretaceous, Spain), in which the frontals remain paired with shallow interorbital constriction ( Bolet & Evans, 2010). In immature specimens of Meyasaurus (Early Cretaceous, Spain) the frontals are paired but during ontogeny they become fused completely and strongly constricted between the orbits ( Evans & Barbadillo, 1997). The only known specimen of Purbicella ragei Evans, Jones & Matsumoto, 2012 (Early Cretaceous, England), consisting of an articulated skull preserved in ventral view, also has fused frontals but with weaker interorbital constriction than in Meyasaurus ( Evans et al., 2012) .

In Aspidoscelis , Callopistes , Teius and Tupinambis the dorsal surface of the fused frontals bears a network of shallow grooves and pits, whereas in Dracaena it is entirely smooth. In Polyglyphanodontia the frontals are weakly ornamented (e.g. Gilmoreteius and Polyglyphanodon ) or completely smooth (e.g. Adamisaurus ) ( Nydam, Caldwell & Fanti, 2010; Gauthier et al., 2012). The triangle-shaped impressions left on the posteroventral parts of the fused frontals in Oardasaurus demonstrate the presence of the ventral lappets of the parietal, a condition known also in Barbatteius , Meyasaurus , Purbicella and other lacertoid lizards ( Estes et al., 1988; Evans & Barbadillo, 1997; Evans et al., 2012; Venczel & Codrea, 2016). Among the polyglyphanodontians, the presence of these ventral lappets has been documented in Tchingisaurus multivagus Alifanov, 1993 , whereas in others (e.g. Adamisaurus , Gilmoreteius , Gobinatus , Polyglyphanodon and Sineoamphisbaena ) the presence of this structure remains uncertain (see Longrich et al., 2012, supplemental material).

Maxilla: Three fragmentary specimens were assigned to this taxon. Their sizes correspond to the other referred cranial bones and the tooth morphology is reminiscent of Barbatteius ( Fig. 5A–G). All examples have pleurodont teeth and bicuspid tooth crowns without any apical striations. Two specimens were listed previously by Jipa [2012: pl. 9: 5a, 5b (ODAN-Amf-8); 6 (ODAN-Amf-9)] under the name ‘Lacertilia indet. dentary/maxillary’.

The specimen PSMUBB.ODAN-A-19 (=ODAN- Amf-8 of Jipa, 2012) ( Fig. 5C–E) is the anterior part of a right maxilla with five intact teeth. The premaxillary and septomaxillary processes are broken away, whereas the ascending nasal process displays several fracture lines and breakages at its dorsal margin. The nasal process exhibits a shallow labial sculpture consisting of pits, ridges and furrows. There are four nutritive foramina displayed in parallel with the maxillary ventral margin. In medial view, the margin of the choanal shelf is damaged exposing small resorption pits at the bases of the preserved teeth. The tooth shaft is cylindrical and projects about one-third beyond the tooth parapet. The tooth crown is bicuspid with a small mesial cusp and a larger distal cusp, both lacking any trace of lingual or labial striation. The tooth morphology of the remaining incomplete specimens (PSMUBB.

ODAN-A-20, 21) ( Fig. 5A, B, F, G, respectively) is closely similar to that of PSMUBB.ODAN-A-19.

Comparisons: Based on the available jaws of Barbatteius (see Venczel & Codrea, 2016) and on the fragmentary specimens referred to Oardasaurus , we may presume that Barbatteiidae possessed a heterodont dentition and the tooth replacement was present in all the marginal teeth. The morphology of the tooth crowns in the maxillae referred to Oardasaurus resembles those of Meyasaurus and Pedrerasaurus (Early Cretaceous, Spain), both having bicuspid tooth crowns with a small mesial cusp and a large distal cusp ( Bolet & Evans, 2010; Sweetman & Evans, 2011: fig. 21.5.C). Conversely, both Meyasaurus and Pedrerasaurus possessed apical striations on their tooth crowns ( Bolet & Evans, 2010; Sweetman & Evans, 2011). The jaws of Barbatteiidae are devoid of enlarged posterior crushing teeth, as seen in many Recent teiids ( Kosma, 2004 and references therein), suggesting that these lizards fed on diverse arthropods, small vertebrates and plants ( Venczel & Codrea, 2016). Furthermore, the marginal teeth of Barbatteiidae differ sharply from those of Polyglyphanodontini and borioteiids possessing highly variable tooth crown patterns as follows: leaf-shaped, policuspate teeth (e.g. Darchansaurus , Erdenetesaurus and Gilmoreteius ); large, bulbous, conical teeth (e.g. Adamisaurus ) and obliquely orientated, chisel-like, policuspate teeth (e.g. Cherminsaurus ) ( Nydam, Eaton & Sankey, 2007; Makádi, 2013 a, b). The highly modified tooth morphology of Polyglyphanodontini and borioteiioids resulted probably from an increased mastication indicated by the relatively precise interdigitation of the upper and lower tooth rows ( Nydam & Cifelli, 2002; Nydam et al., 2007; Nydam, 2013). Tooth replacement was suppressed in the adults of many taxa (e.g. Polyglyphanodon , Paraglyphanodon , Dicothodon and Peneteius ) ( Nydam et al., 2007), while in others, such as Bicuspidon and Distortodon , resorption pits were present indicating that tooth replacement was not suppressed ( Nydam & Cifelli, 2002; Makádi, 2013b and references therein).

BARBATTEIDAE INDET. A

Articular complex: The specimen PSMUBB. ODAN-A-22 ( Fig. 5J, K), represents an incomplete left fused articular-prearticular. Similar to Barbatteius , it lacks a prearticular crest ( Venczel & Codrea, 2016), but a distinct pterygoideus process of roughly triangle shape is apparent on its medial surface. The bone also lacks the remnants of a surangular, suggesting that it was not fused to the prearticular. The retroarticular process extends straight backward and is not inflected medially. The lateral margin of the retroarticular process is damaged, thus it cannot be demonstrated if it was wider or narrower distally than the mandibular condyle.

Comparisons: Typical for the lower jaw of teiids is the presence of a well-developed prearticular crest with the pterygoideus process imbedded in it ( Conrad, 2008). In lacertids the prearticular is devoid of prearticular crest and pterygoideus process, whereas in Meyasaurus the prearticular crest is faintly developed and the pterygoideus process is triangle shaped ( Evans & Barbadillo, 1997). In Barbatteius the prearticular crest is lacking and the apex of the triangle-shaped pterygoideus process projects forward.

BARBATTEIDAE INDET. B

Dentary: The specimen PSMUBB.ODAN-A-24 represents an incomplete dentary of a relatively small individual with its posterior part broken away ( Fig. 5H, I). Anteriorly, the bone is slender and faintly curved lingually; however, it becomes deeper posteriorly. The subdental shelf is narrow and the Meckelian canal is open up to the symphysis. The symphyseal region is relatively small, restricted to the four anteriormost teeth. Twenty-one tooth positions are preserved in the specimen and the mandibular septum is situated at the level of the 20th tooth position. Unfortunately, all the tooth crowns are broken away. However, the tooth shafts indicate that the teeth were cylindrical, possessing at their base small circular resorption pits. The labial surface of the dentary is smooth and ten mental foramina are preserved, arranged in a single row.

Comparison: Despite the considerable size difference, PSMUBB.ODAN-A-24 resembles Barbatteius in having a relatively small symphyseal region, a fully open Meckelian canal anterior to the symphysis, a relatively narrow subdental shelf and the tooth replacement being present in all dentary teeth. Unfortunately, the tooth crowns are not preserved and therefore a closer assignment of the specimen is impossible.

NOTES ON THE EVOLUTIONARY HISTORY AND PALAEOBIOGEOGRAPHY OF BARBATTEIIDAE

In spite of the differences seen in the pattern of osteodermal sculpturing, pileus morphology and reconstructed body size of Barbatteius (early Maastrichtian of Pui locality, Haţeg Basin; reconstructed total body length of about 800 mm) and Oardasaurus (late early Maastrichtian of Oarda de Jos locality, Transylvanian Basin; reconstructed total body length of about 200 mm), their skull roofing bones (parietal, fused frontals, postorbital) share a combination of diagnostic features. The most important attributes are preserved on the parietal, as follows: extensive osteodermal sculpture is present and strongly fuses to the parietal and supratemporal processes; the osteodermal crust bears also the impressions of cephalic scales; the jaw adductor muscles insert dorsally on the parietal (i.e. invading the outer surfaces of the descending flanges) and supratemporal processes; the upper temporal fenestra is not occluded by either the postorbital and/ or the postfrontal. The frontals, if correctly assigned to Oardasaurus , reveal further important morphological features as follows: they are fused completely with markedly concave orbital margins; similar to Barbatteius , an extensive osteodermal crust is present with a slightly different sculptural pattern than that of the parietal; the existence of ventral lappets of the parietal are documented as triangular impressions, posterior to crista cranii frontalis. The only incomplete postorbital referred to Oardasaurus also possesses an osteodermal sculpture similar to that of the parietal. The smooth medial margin of that specimen indicates that it bordered from lateral an unoccluded upper temporal fenestra.

Excepting Barbatteiidae and Meyasaurus , no other Cretaceous lizards possess on the skull roofing bones the following unique combination of features: (1) presence of osteodermal sculpture that bears the impressions of cephalic scales and (2) jaw adductor muscles originate dorsally on the parietal table and supratemporal processes. Furthermore, up to the present, the fossil record lacks any known evidence of lizards comparable to Barbatteiidae from the well-studied Palaeogene deposits of Western Europe (e.g. Augé, 2005; Čerňanský, Klembara & Műller, 2016 and references therein), suggesting that this group apparently did not survive the K/Pg boundary.

Previously, the phylogenetic relationships of Barbatteius were tested by parsimony analyses (see Venczel & Codrea, 2016, supplemental material), based on 196 morphological characters scored on the holotype and added to the datasets of Gauthier et al. (2012) and Longrich et al. (2012). Inclusion of Barbatteius and implicitly of Barbatteiidae within Teiioidea is supported among others by the following synapomorphies: 36(1) frontals fused and 314(1) prootic forms part of medial aperture recessus scalae tympani. Barbatteius and Teiidae (included taxa: Aspidoscelis tigris , Callopistes maculatus , Teius teyou and Tupinambis teguixin ) share the following unambiguous synapomorphies: 78(2) postorbital overlaps the squamosal dorsally, 90(0) parietal temporal muscles originate dorsally on the parietal table and parietal supratemporal processes, 294(1) epipterygoid – parietal contact overlaps parietal temporal muscle origin and 360(1) weakly developed subdental shelf ( Venczel & Codrea, 2016).

The presence of Meyasaurus in pre-Cenomanian times of cratonic Europe suggests an early northward distribution of teiioids, probably from Gondwanan territories. However, it is still unclear whether Barbatteiidae , known exclusively from the latest Cretaceous Transylvanian Landmass, may have been the closest relatives of Meyasaurus , because nothing is known about their postcranial skeleton. This also raises the question of whether Barbatteiidae could have been related to the teiid-like Polyglyphanodontidae , which have also been recorded from ‘Haţeg Island’, Romania (e.g. Bicuspidon hatzegiensis ; Folie & Codrea, 2005). Gilmore (1942) supposed that the polyglyphanodontians were closely allied to Iguania, but owing to their peculiar dentition (i.e. heterodont and transversely widened crowns in the posterior teeth) and tooth implantation (i.e. subacrodont mode of insertion without sign of tooth replacement) placed them in a separate family. Conversely, Hoffstetter (1962) and Estes (1964, 1969) argued that polyglyphanodontians may be referred to teiids (see also Presch, 1983; Gao & Norell, 2000; Nydam, 2002; Nydam & Cifelli, 2005) and subsequently the group was included within ‘macroteiids’ (e.g. Estes, 1983; Estes et al., 1988) or Macroteiida ( Conrad, 2008). Another group of teiid-like lizards is the Borioteiioidea that clusters a number of Late Cretaceous lizards including Polyglyphanodontini (e.g. Polyglyphanodon , Paraglyphanodon , Peneteius and Dicothodon )( Nydam et al., 2007), the unnamed clade of Cherminsaurus and Gilmoreteius (= Macrocephalosaurus ) that stands as the sister taxon of Polyglyphanodontini [(these two clades being equivalent of Estes’ (1983) Polyglyphanodontinae)] and the Chamopsidae ( Chamops , Gerontoseps, Harmondontosaurus , Haptosphenus , Leptochamops , Meniscognathus , Socognathus , Stypodontosaurus and Tripennaculus ) ( Nydam, Caldwell & Fanti, 2010). A maximum parsimony tree resulting from the analysis of phenotypic data of Gauthier et al. (2012) and Longrich et al. (2012) places Polyglyphanodontidae outside Teiidae positioning them on the scleroglossan stem, rather than the scleroglossan crown, a topology that shifts the origin of this clade back into the Late Jurassic ( Gauthier et al., 2012). However, the latter assumption is not currently supported by the fossil record, because polyglyphanodontians appear relatively late (i.e. Late Cretaceous) in the fossil record starting to dominate lizard communities (e.g. in Asia) in the Late Cretaceous ( Gao & Norell, 2000). Finally, the results of combined morphological and molecular likelihood analyses of Reeder et al. (2015) indicate that polyglyphanodontians (included genera were Adamisaurus , Gilmoreteius , Gobinatus , Polyglyphanodon and Tchingisaurus ) are crown lizards and sister taxon of Iguania ( Reeder et al., 2015: fig. 1), in support of the earlier conclusions of Gilmore (1942).

The members of Barbatteidae, when reaching the Transylvanian landmass in the latest Cretaceous, probably underwent an adaptive radiation within the relatively complex terrestrial ecosystems of ‘Haţeg Island’. Conversely, the fossil record of the polyglyphanodontid-borioteiid grade lizards from ‘Haţeg Island’ may represent the latest Cretaceous radiation of a more advanced toxicopheran lizard clade that originated in Euramerica or Asia.

The main aspect of the squamate fauna from the latest Cretaceous of the Transylvanian landmass refers to its unexpectedly high faunal diversity that ensures a number of archaic forms are preserved therein, such as paramacellodids ( Becklesius cf. B. hoffstetteri and B. nopcsai ) ( Folie & Codrea, 2005), large- and medium-sized teiioids ( Barbatteius vremiri and Oardasaurus glyphis ), still undetermined geckonids and scincids (MV, personal observation), small-sized madtsoiid snakes ( Vasile et al., 2013) and indeterminate madtsoiids ( Folie & Codrea, 2005), together with more advanced polyglyphanodontid-borioteiid grade lizards (e.g. Bicuspidon ) and anguimorphs ( Grigorescu et al., 1999). The sister taxon relationships of Barbatteius (a gigantic-sized teiioid) and Oardasaurus (a medium-sized teiioid) indicate the long-term persistence of quite complex ecosystems in the Transylvanian landmass, where a number of closely related forms may have differentiated in time to occupy various ecological niches.