Tarentola Annularis Research Articles

Lingual adaptations of the Tarentola annularis with new insights into its papillary system adaptations: Ultrastructure, histochemistry, and immunohistochemical observations

Our research aims to conduct a comprehensive ultrastructural, histochemical, and immunohistochemical examination of Tarentola annularis' tongue, utilizing various techniques such as light, scanning electron microscopy, and morphometric analysis. The complex papillary system consisted of four conical subtypes and one filiform type. The apex carried three conical subtypes (elongated, quadrilateral, and round); the midtongue carried two papillary types (quadrilateral conical and rectangular pointed filiform); and the hindtongue carried two conical subtypes (quadrilateral and elongated serrated). The dorsal papillary surface carried little taste pores on the foretongue and taste buds on the midtongue. The foretongue had a slightly stratum corneum that spread to coat the papillae, while the mid- and hindtongue did not. The glands are absent from the foretongue but are found in the interpapillary spaces of the mid- and hindtongue. Histochemical analysis reveals the presence of collagen fibers in the muscle bundles and the papillary core. The midtongue glands exhibited a strong reaction to AB and PAS, while the hindtongue showed moderate AB positivity and strong positive PAS. The cytokeratin expression in the foretongue papilla was positive, whereas the papillae in other regions were negative. The Tarentola annularis exhibits distinctive lingual structural characteristics due to its varied feeding habits influenced by available food particles.

Seasonal remodeling of visceral organs in the invasive desert gecko Tarentola annularis.

In winter, many reptiles have a period of inactivity ("brumation"). During brumation there is no energetic intake, therefore there would be an advantage to reducing energetic expenditure. The size of energetically costly organs, a major determinant of metabolic rate, is known to be flexible in many tetrapods. Seasonal plasticity of organ size could serve as both an energy-saving mechanism and a source of nutrients for brumating reptiles. We studied a population of an invasive gecko, Tarentola annularis, to test for seasonal changes in activity, metabolic rate, and mass of various organs. The observed period of inactivity was December-February. Standard metabolic rates during the activity season were 1.85 times higher than in brumating individuals. This may be attributed to decreased organ mass during winter: heart mass decreased by 37%, stomach mass by 25%, and liver mass by 69%. Interestingly, testes mass increased by 100% during winter, likely in preparation for the breeding season, suggesting that males prioritize breeding over other functions upon return to activity. The size of the kidneys and lungs remained constant. Organ atrophy occurred only after geckos reduced their activity, so we hypothesize that organ mass changes in response to (rather than in anticipation of) cold winter temperatures and the associated fasting. Degradation of visceral organs can maintain energy demands in times of low supply, and catabolism of the protein from these organs can serve as a source of both energy and water during brumation. These findings bring us closer to a mechanistic understanding of reptiles' physiological adaptations to environmental changes.

Comparative ultrastructural study of the oropharyngeal cavity roof in Tarentola annularis and Heremites vittatus: To special reference to palate adaptation with feeding habits

No studies have yet been conducted on the morphology and characteristics of the oropharyngeal cavity roof in various reptiles, particularly lizards and Gecko. This study aimed to provide a comprehensive analysis of the oropharyngeal cavity roof morphology and characteristics of T. annularis and H. vittatus. Both species have a palate of two parts: the rostral choanal vomeral part and the caudal part. The rostral palatine part is slightly longer due to a diastema. The palate is more triangular in H. vittatus than in T. annularis. The palatine papilla in H. vittatus is slightly elevated and separated from the incisive teeth by a transverse ridge, while in T. annularis; it is caudal to the incisive teeth. Both species have two cleft-like choana between the premaxillary and the maxillary bones. The caudal palatine part of T. annularis has two elevated tubercles, while H. vittatus carries 2–4 longitudinal ridges. T. annularis has three ridges: one median (which extends into the caudal part) and two transverse ridges, while H. vittatus had one transverse dental ridge and two mucosal folds. The rostral palatine part of T. annularis had glandular openings and taste pores with a taste process, while H. vittatus had numerous glandular openings only.

Embryonic development of the skull in a parthenogenetic lizard, the mourning gecko (Lepidodactylus lugubris).

Gekkotans are one of the major clades of squamate reptiles. As one of the earliest-diverging lineages, they are crucial in studying deep-level squamate phylogeny and evolution. Developmental studies can shed light on the origin of many important morphological characters, yet our knowledge of cranial development in gekkotans is very incomplete. Here, we describe the embryonic development of the skull in a parthenogenetic gekkonid, the mourning gecko (Lepidodactylus lugubris), studied using non-acidic double staining and histological sectioning. Our analysis indicates that the pterygoid is the first ossifying bone in the skull, as in almost all other studied squamates, followed closely by the surangular and prearticular. The next to appear are the dentary, frontal, parietal and squamosal. The tooth-bearing upper jaw bones, the premaxilla and maxilla, develop relatively late. In contrast to previous reports, the premaxilla starts ossifying from two distinct centres, reminiscent of the condition observed in diplodactylids and eublepharids. Only a single ossification centre of the postorbitofrontal is observed. Some of the endochondral bones of the braincase (prootic, opisthotic, supraoccipital) and the dermal parasphenoid are the last bones to appear. The skull roof is relatively poorly ossified near the time of hatching, with a large frontoparietal fontanelle still present. Many bones begin ossifying relatively later in L. lugubris than in the phyllodactylid Tarentola annularis, which suggests that its ossification sequence is heterochronic with respect to T. annularis.

Reproductive and Morphological Characteristics of Hemidactylus turcicus (Squamata: Gekkonidae) and Tarentola annularis (Squamata: Phyllodactylidae) in Southern Egypt

Hemidactylus turcicus and Tarentola annularis are occasionally sympatric and are ecologically similar in vertical wall microhabitat. For this reason, I studied their sexual, fat-body, and liver cycles for three years. All morphological variables are male-biased in T. annularis, unlike male H. turcicus, which showed significant differences in head sizes only. Females exhibited a spring to summer vitellogenic period with ovulation occurring during mid-spring to mid-summer in T. annularis and from late spring to late summer in H. turcicus. The mean clutch size of oviductal eggs (1.86) and relative clutch mass (0.188) was higher in H. turcicus than in T. annularis (1.67 and 0.132). Relative clutch mass was negatively correlated with snout–vent length in T. annularis but was not in H. turcicus. Sperm were present in the epididymis for eight months in H. turcicus while year-round in T. annularis. Post-breeding, masses of liver and fat body increased in both sexes of both species. There were significant differences in fat body and liver masses between the sexes of both species. Based on the liver-mass cycle, the energy expenditure on reproduction in male and female T. annularis was high compared with the corresponding sexes of H. turcicus. Testicular recrudescence began in late fall or early winter corresponding to lower temperatures, photoperiod, and precipitation. Testicular regression occurred at the highest temperatures in late summer and early fall.

Reassignment of Haemogregarina annularis from the Blood of Tarentola annularis to the Genus Hepatozoon Based on the Parasite Morphology and 18S rDNA Sequence Analysis.

To date, two haemogregarines have been described from the white-spotted wall gecko, Tarentola annularis in Egypt. These species are Haemogregarina annularis and Haemogregarina tarentannulari. Although these two species initially were described as different species parasitizing T. annularis, both forms look identical due to their similar morphology and morphometric characteristics from the same host species. Here we will clarify, using traditional morphological description of the blood and tissue stages, combined with molecular analysis, the identity of the haemoparasites infecting T. annularis in Egypt. Thin blood smears were screened from 50 gecko, Tarentola annularis and merognic stages were identified in the lung of the infected geckos. Parasite DNA was extracted and PCR was carried out to amplify parasite 18S rDNA. Morphological criteria of parasite stages, mature gamont stages and mergonic stages were similar to the two previously reported Haemogregarina species. In the phylogenetic tree, the present haemogregarine fell within a clade comprising most of Hepatozoon species infecting reptiles. Our morphological comparison supported that the two previously described Haemogregarina species were the same and allowed us to consider Haemogregarina tarentannulari as a junior synonym of Haemogregarina annularis. Our phylogenetic analysis gave us the opportunity to reassign Haemogregarina annularis to the genus Hepatozoon and being identified as Hepatozoon annularis n. comb.

Detection of Leishmania tarentolae in lizards, sand flies and dogs in southern Italy, where Leishmania infantum is endemic: hindrances and opportunities

BackgroundLeishmania tarentolae is a protozoan isolated from geckoes (Tarentola annularis, Tarentola mauritanica), which is considered non-pathogenic and is transmitted by herpetophilic Sergentomyia spp. sand flies. This species occurs in sympatry with Leishmania infantum in areas where canine leishmaniasis is endemic. In the present study, we investigated the circulation of L. tarentolae and L. infantum in sand flies, dogs and lizards in a dog shelter in southern Italy, where canine leishmaniasis by L. infantum is endemic.MethodsSheltered dogs (n = 100) negative for Leishmania spp. (March 2020) were screened by immunofluorescence antibody test (IFAT) using promastigotes of both species at two time points (June 2020 and March 2021). Whole blood from dogs, tissues of Podarcis siculus lizards (n = 28) and sand flies (n = 2306) were also sampled and tested by a duplex real-time PCR (dqPCR). Host blood meal was assessed in sand flies by PCR.ResultsOverall, 16 dogs became positive for L. infantum and/or L. tarentolae by IFAT at one or both sampling periods. One canine blood sample was positive for L. infantum, whilst two for L. tarentolae by dqPCR. At the cytology of lizard blood, Leishmania spp. amastigote-like forms were detected in erythrocytes. Twenty-two tissue samples, mostly lung (21.4%), scored molecularly positive for L. tarentolae, corresponding to 10 lizards (i.e., 35.7%). Of the female Sergentomyia minuta sampled (n = 1252), 158 scored positive for L. tarentolae, four for L. infantum, and one co-infected. Two Phlebotomus perniciosus (out of 29 females) were positive for L. tarentolae. Engorged S. minuta (n = 10) fed on humans, and one P. perniciosus, positive for L. tarentolae, on lagomorphs.ConclusionsDogs and lacertid lizards (Podarcis siculus) were herein found for the first time infected by L. tarentolae. The detection of both L. tarentolae and L. infantum in S. minuta and P. perniciosus suggests their sympatric circulation, with a potential overlap in vertebrate hosts. The interactions between L. tarentolae and L. infantum should be further investigated in both vectors and vertebrate hosts to understand the potential implications for the diagnosis and control of canine leishmaniasis in endemic areas.Graphical abstract

Prevalence and intensity of haemoparasites infecting the white-spotted gecko, Tarentola annularis in Sudan.

Thirty-five white-spotted geckos, Tarentola annularis were collected from Shendi area, River Nile State, Sudan, between June and September 2019 and examined for the presence of haemoparasites infection. Six (17.14%) geckos were found to be positive for intra erythrocytic haemogregarine (Apicomplexa: Haemogregarinidae) species with a mean overall infection intensity of 1.20% ± 0.32 and parasitemia level between ~0.70% and ~1.70%. However, most parasite gamonts were found intracellular, and no damage on the infected erythrocytes was observed. The prevalence of infection between adult and juvenile geckos was significantly different (P = 0.012); however, no substantial difference between males and females was found. On the other hand, the mean intensity of infection did not differ between adult and juvenile geckos. In conclusion, no obvious negative impact on the local T. annularis gecko community was observed due to haemogregarine species infection.

Embryonic skull development in the gecko, Tarentola annularis (Squamata: Gekkota: Phyllodactylidae).

Tarentola annularis is a climbing gecko with a wide distribution in Africa north of the equator. In the present paper, we describe the development of the osteocranium of this lizard, from the first appearance of the cranial elements up to the point of hatching. This is based on a combination of histology and cleared and stained specimens. This is the first comprehensive account of gekkotan pre-hatching skull development based on a comprehensive series of embryos, rather than a few selected stages. Given that Gekkota is now widely regarded as representing the sister group to other squamates, this account helps to fill a significant gap in the literature. Moreover, as many authors have considered features of the gekkotan skull and skeleton to be indicative of paedomorphosis, it is important to know whether this hypothesis is supported by delays in the onset of cranial ossification. In fact, we found the sequence of cranial bone ossification to be broadly comparable to that of other squamates studied to date, with no significant lags in development.

Ontogeny of the Moorish gecko Tarentola mauritanica with emphasis on morphogenesis of the skin and its derivatives.

Studying reptilian embryonic development provides answers to many questions related to the development of tetrapods. Reptilian skin has been recently considered in studies at the evo-devo level. The lizard epidermis has to be shed periodically. At the embryonic level, contention exists regarding the first layers to appear, whether the oberhautchen or the clear layer, and whether the shedding complex develops before hatching. Geckos exhibit diverse morphologies independently evolved multiple times within the clade, such as subdigital pad lamellae. Here we investigate the embryonic development of Tarentola mauritanica and establishing its embryonic table. Primarily we follow the development of the integument. This is a closely related species to Tarentola annularis and it is crucial to investigate whether it has the same derived digital condition of claw regression. Eleven embryonic stages are described according to the external morphological characteristics of the embryos. Interestingly, the oviposition stage appears earlier than its close relative T. annularis, and the total incubation time is less. We also describe skin development, adding clear evidence to the debate on the development of the shedding complex, which we found is developed before hatching. We describe one layer of periderm and the clear layer as the first embryonic epidermal layers. Generally, our results show the genus Tarentola to have the advantage of being a unique taxon, easily breed at the laboratory, with multiple clutches per year, and with an earlier stage at oviposition. That could be a model animal for embryonic development and experimental embryology studies.

Morphological redescription and phylogenetic assessment of Spauligodon aspiculus (Oxyuroidea: Pharyngodonidae) infecting the white-spotted gecko, Tarentola annularis (Squamata: Gekkonidae).

Thirty white-spotted geckos, Tarentola annularis, from the South Sinai desert in Egypt, were examined for helminth parasites. Spauligodon aspiculus was observed to infect 19 geckos with 63.33% as a prevalence of parasitic infection. The present nematode species is separated from congeners by morphological and metrical characteristics such as lateral alae, aspinose filamentous tail, and no spicule, and three pairs of caudal papillae with posterior pair excluded from envelopment by the caudal alae in the male worms, and knobbed eggs, and postbulbar vulva in females. It compared morphometrically with other Spauligodon species described previously and showed few differences in measurements. Molecular characterization based on the partial 28S rRNA nuclear ribosomal gene sequence showed that there was a close identity, up to 72%, with other sequences retrieved from GenBank. Phylogenetic analysis showed that the parasite sequence in conjunction with existing data facilitates the investigation of the placement of this pharyngodonid species within Oxyuridae. The present species is deeply embedded in the genus Spauligodon with close relationships to previously described Spauligodon nicolauensis (gb| JN619349.1, and JF829243.1) as more related sister taxa. This study highlights the importance of combining genetic and morphological data with taxonomy in pharyngodonid species.

Helminth parasites of the white-spotted wall gecko, Tarentola annularis (Squamata: Gekkonidae), from Shendi area, Sudan

This is the first report on helminths parasitize the white-spotted wall gecko, Tarentola annularis from Shendi area in Sudan. A total of 32 geckos were collected between January and May 2018, and examined for helminth infections. Three nematode species of the family Pharyngodonidae were identified: Pharyngodon mamillatus, Spauligodon brevibursata and Parapharyngodon sp. The most prevalent nematode found was P. mamillatus followed by S. brevibursata. The overall prevalence and intensity of infections was 81.3% and 6.8 nematodes per one infected gecko, respectively. The prevalence and intensity of infections were observed to be more in adult male geckos compared to adult females. On the other hand, the prevalence and intensity of infections were significantly higher in adult geckos compared to the juveniles.

Fine structure of the dorsal lingual epithelium in Tarentola annularis and Crocodylus niloticus.

The present study examined the morphological features, histological and histochemical aspect of the tongue of two reptilian species, Tarentola annularis (family: Gekkonidae) and Crocodylus niloticus (family: Crocodylidea), with different habitats, feeding patterns and behaviours, by light and scanning electron microscope. It was observed, that the bifurcation of the tongue was more visible in Tarentola annularis. Conical and filamentous papillae were observed on the lingual body of Tarentola annularis, while in Crocodylus niloticus both mechanical filiform and gustatory papillae appeared. The lingual mucosa in Tarentola annularis is covered by stratified squamous epithelium and keratinised but in Crocodylus niloticus it is highly folded and more heavily keratinised in the folded region and have a localised thickenings structure resembling taste buds. Mucous glands appeared in Tarentola annularis and compound tubular glands in Crocodylus niloticus. At scanning electron microscopy, abundant microridges and microvilli in both species were exhibited on papillae surface facilitated feeding habits. Histochemically, the tongue of two species is strongly positive for carbohydrate stain but with variable degree with others stains. In conclusion, there is a marked correlation between the structure of the tongue of the present reptilian species, habitats and feeding mechanism of the two species.

Armored geckos: A histological investigation of osteoderm development in Tarentola (Phyllodactylidae) and Gekko (Gekkonidae) with comments on their regeneration and inferred function.

Osteoderms are bone-rich organs found in the dermis of many scleroglossan lizards sensu lato, but are only known for two genera of gekkotans (geckos): Tarentola and Gekko. Here, we investigate their sequence of appearance, mode of development, structural diversity and ability to regenerate following tail loss. Osteoderms were present in all species of Tarentola sampled (Tarentola annularis, T. mauritanica, T. americana, T. crombei, T. chazaliae) as well as Gekko gecko, but not G. smithii. Gekkotan osteoderms first appear within the integument dorsal to the frontal bone or within the supraocular scales. They then manifest as mineralized structures in other positions across the head. In Tarentola and G. gecko, discontinuous clusters subsequently form dorsal to the pelvis/base of the tail, and then dorsal to the pectoral apparatus. Gekkotan osteoderm formation begins once the dermis is fully formed. Early bone deposition appears to involve populations of fibroblast-like cells, which are gradually replaced by more rounded osteoblasts. In T. annularis and T. mauritanica, an additional skeletal tissue is deposited across the superficial surface of the osteoderm. This tissue is vitreous, avascular, cell-poor, lacks intrinsic collagen, and is herein identified as osteodermine. We also report that following tail loss, both T. annularis and T. mauritanica are capable of regenerating osteoderms, including osteodermine, in the regenerated part of the tail. We propose that osteoderms serve roles in defense against combative prey and intraspecific aggression, along with anti-predation functions.

Developmental stages of the climbing gecko Tarentola annularis with special reference to the claws, pad lamellae, and subdigital setae.

Studying the in ovo mode of development of squamates has the advantage of allowing easy access to embryos without surgically compromising gravid females. Despite the non-ophidian squamates being a very diverse lineage of reptiles, embryonic tables for individuals of this group are very few. Here, I present the first in ovo embryonic table for a basal multi-scansored, pad-bearing gecko, Tarentola annularis. In this gecko, only the III and IV digits bear claws. Eleven embryonic stages are described based on chronological development of morphological characteristics. In contrast to other previously studied geckos, this species exhibits a longer incubation period. Comparison with other squamates, embryonic development of T. annularis is an indicative of a conserved developmental strategy. Interestingly, the clawless digits of this gecko do exhibit claws during the first half of embryonic development. Thus, regression of claws in these digits could be an advantage of studying this particular taxon, as it raises the question, to be answered in future study, of which mechanisms could be responsible for such claw regression. Before hatching, the outer periderm layer sloughs revealing the functional setae. The present study provides not only a model for pentadactyl limbs and digit development, but also an example of a unique developmental phenomenon, as represented by claw regression.

A description of Haemogregarina species naturally infecting white-spotted gecko (Tarentola annularis) in Qena, Egypt.

The present study describes the developmental stages of Haemogregarina species in the blood and tissues of naturally infecting white-spotted gecko Tarentola annularis collected from Qena, Egypt. Different parasite's forms were observed infecting the erythrocytes. The gamonts enclosed within parasitophorous vacuole and seems to have no clear effect on the host cell especially in case of immature parasite forms. But in the presence of mature gamonts the host cell nucleus displaced. The parasitaemia level is up to 280 per 10,000 erythrocytes counted. Trophozoites and gamonts have been recognized in the blood smears. The rounded trophozoite diameter is 3.84 ±0.87 μm, while the elongated trophozoite measured 4.42 ± 0.69 x 2.8 ± 0.56 μm. The mature gamonts were differentiated into two forms; short gamont measuring 10.82 ± 0.82 x 3.30 ± 0.73 μm (range: 10-12.1 x 2.2-4.4 μm) and the long gamont measured 14.67 ± 0.83 x 3.96 ± 0.77 μm (range: 14.1-16.5 x 3.3-5.5 μm). Merogony carried out only in the endothelial cells of the blood capillaries in the lung. Different merogonic stages have been recognized and differentiated in two forms; micromeront measured 13.25 ± 0.50 x 12 ± 0.0 μm and produces a few number of large merozoites, macromeront measured 19.75+0.87x13.25+0.50 im and produces more small sized merozoites. The gamonts and merozoites have the general characteristic ultrastructures of the Apicomplexa containing components of the apical complex, e.g. pellicle, micronemes, rhoptries, and few dense bodies and subpellicular microtubules.

Redescription of two nematode parasites infecting Reptilia in Qena Governorate

During a helminthological examination of Tarentola annularis (Geoffroy, 1828) and Chalcides ocellatus (Forskal, 1775), 12 out of 60 Tarentola annularis were found to harbour a large number of Spauligodon aspiculus, 30 out of 106 Chalcides ocellatus were found to harbour Thelandros aegypti.

COCCIDIAN BLOOD INFECTIONS OF LIZARDS IN EGYPT

The infection rates of coccidian blood parasites in the common lizards (Gekkonidae: Ptyodactylus hasselquistii, Tarentola annularis, Hemidactylus turcicus; Scincidae: Chalcides ocellatus, Chalcides sepsoides, Mabuya quinquetaeniata; Varanidae: Varanus niloticus and Lacertidae: Acanthodactylus boskianus) in Qena (Egypt) were investigated; 67 lizards (42%) out of 161 lizards were infected. The infection rate was 49% among males and 37% among females. The highest infection rate was found in the Gekkonidae P. hasselquistii (100%) and T. annularis (74%). However, 17% of H. turcicus, were parasitized. Meanwhile, in the Scincidae C. ocellatus, C. sepsoides and M. quinquetaeniata the percentage of the infection was 23%, 17% and 14%, respectively. Only one V. niloticus (Varanidae) was infected. None of A. boskianus (Lacertidae) were parasitized. Seasonal variations of infection rates seem to occur in T. annularis, in which high rates were found in summer (100%) and winter (77.8%). All P. hasselquistii were infected with Karyolysus sp., and 56% contained a mixed infection with Plasmodium sp., resulting in parasitaemia up to 14%. About 30% of T. annularis infections were due to Lankesterella sp., the others were due to Haemogregarina sp., both together infecting up to 6%. Lankesterella species was found in 0.02% of H. turcicus. The parasitaemia in Scincidae were 75% in C. ocellatus and 0.02% in C. sepsoides. In M. quinquetaeniata, up to 12% of blood cells possessed Hepatozoon sp. and in V. niloticus up to 0.5% was infected with Haemogregarina sp.

Phylogenetic relationship among five geckos from Egypt based on RAPD-PCR and protein electrophoresis (SDS–PAGE)

Genetic variations between five gekkonid species from Egypt; Tropiocolotes tripolitanus, Tropiocolotes steudneri, Tropiocolotes nattereri, Tarentola mauritanica and Tarentola annularis were analyzed by SDS–PAGE for water soluble proteins and random amplified polymorphic DNA (RAPD) analysis. Based on SDS–PAGE of water soluble proteins for all species, the obtained results revealed a total of 17 bands at molecular weights that ranged from 95 to 16kDa. The polymorphic bands among species were 11 (64.7%) and the mean similarity matrix value between them was 70.7%. Using RAPD-PCR, the results showed eight total amplified bands at molecular weights that ranged from 1408 to 360bp. The polymorphic bands between species were 7 (87.5%) and the mean similarity matrix between them was 44.6%. The dendrogram showed that, the five gekkonid species are separated from each other into two clusters. The first cluster contains three species of the genus Tropiocolotes. The second cluster includes the two species of the genus Tarentola. Based on SDS–PAGE and RAPD-PCR results, T. nattereri is sister to T. steudneri with higher genetic similarity than with T. tripolitanus. It is concluded that, the similarity coefficient and the genetic distance values between the five gekkonid species indicate that the five gekkonid species are not identical and are separated from each other. From these results, it is indicated that the protein and RAPD analysis are useful molecular tools to indicate genetic variation between the species in the same genus or in the different genera.

An Osteological and Histological Investigation of Cranial Joints in Geckos

Cranial kinesis is a widespread feature of gekkotan lizards. Previous studies of kinesis in lizards often described the relevant, mobile joints as synovial, thus characterized by the presence of a synovial cavity lined with articular cartilage. To date however, detailed investigations of cranial joint histology are lacking. We examined eight cranial joints (quadrate-articular, quadrate-pterygoid, quadrate-otooccipital, quadrate-squamosal, epipterygoid-prootic, epipterygoid-pterygoid, basisphenoid-pterygoid, and frontal-parietal) in five gekkotan species (Oedura lesueuerii, Eublepharis macularius, Hemitheconyx caudicinctus, Tarentola annularis, and Chondrodactylous bibronii) using microcomputed tomography and serial histology. Particular focus was given to the relationship between the bony and soft-tissue components of the joint. Our results demonstrate that only three of these joints are synovial: the quadrate-articular, epipterygoid-pterygoid, and basisphenoid-pterygoid joints. The frontal-parietal and quadrate-pterygoid joints are syndesmosis (fibrous), the epipterygoid-prootic and quadrate-otooccipital joints are synchondroses (cartilaginous without a synovial cavity) and the quadrate-squamosal joint was not present. Based on previous descriptions, we determine that the structure of some cranial joints is variable among lizard taxa. We caution that osteology does not necessarily predict cranial joint histology. Although the functional implications of these findings remain to be explored we note that the development of synovial joints appears to be associated with a neural crest origin for the elements involved.