Uromastyx Hardwickii Research Articles

Hotter deserts and the impending challenges for the Spiny-tailed Lizard in India.

Ectotherms are particularly vulnerable to climate change, especially those living in extreme areas, such as deserts, where species are already thermally constrained. Using the vulnerable herbivorous lizard Saara hardwickii as a model system, we used a multi-pronged approach to understand the thermal ecology of a desert agamid and potential impacts of rising temperatures. Our data included field-based measures of operative temperatures, body temperatures, and activity, as well as lab-based measures of thermal limits, preferences, and sprint speed. As expected, the temperature dependence of locomotor performance and foraging activity were different, and in the worst-case global warming scenario (SSP5-8.5), potential sprint speed may decrease by up to 14.5% and foraging activity may decrease by up to 43.5% by 2099. Burrows are essential thermal refuges, and global warming projections suggest that S. hardwickii may be restricted to burrows for up to 9 h per day by 2099, which would greatly limit critical activities, like foraging and seeking mating opportunities. Overall, we show that key information on thermal ecology, including temperature-sensitive behaviours in the wild, is necessary to understand the multiple ways in which increasing temperatures may influence ectothermic vertebrates, especially for species like S. hardwickii that are already vulnerable to environmental change.

Genetic variations and phylogenetic relationship of genus Uromastyx from Punjab Pakistan.

During the present study, specimens were collected from selected sites of Cholistan desert and Kalabagh Game Reserve, Punjab province, Pakistan. Each captured specimen was tagged with voucher number and morphometric measurements were taken. The average snout to vent length was 172.559±1.40 mm and average weight was 92.1±1.30 g. The DNA of Uromastyx hardwickii was amplified and sequenced using 16S rRNA primer set. The obtained DNA sequence has shown reliable and clear species identification. After trimming ambiguous bases, the obtained 16S rRNA fragment was 520 bp while 16S rRNA fragments aligned with closely matched sequence from NCBI comprised of 510 bp. Closely matched sequences of genus Uromastyx were retrieved from NCBI in blast searches. Neighbour-joining tree of genus Uromastyx was constructed based on p-distance using MEGA X. The mean intraspecific variation was 0.095±0.01 while intraspecific variation was ranging from 0-1%. Similarly, interspecific variation of Uromastyx hardwikii with Saara asmussi, Uromastyx alfredschmidti, Uromastyx geyri, Uromastyx thomasi, Uromastyx alfredschmidti was 0-12%, 0-19%, 0-19%, 0-20%, 12-19% respectively. The newly produced DNA was submitted to NCBI and accession number was obtained (MW052563.1). Results of current study provided information about the molecular and morphological identification of Genus Uromastyx. In our recommendation, comprehensive molecular based identification of Pakistan's reptiles is required to report any new or subspecies from country.

Antidiabetic effects of ethanol extract of Uromastyx hardwickii Smith (Agamidae) skin on streptozotocin-induced diabetes mellitus in mice


 
 
 
 Purpose: To investigate the in vivo hypoglycemic potential of the ethanol extract of Uromastyx hardwickii skin (EEUHS).
 Methods: Streptozotocin-induced diabetic mice received graded doses (100 and 200 mg/kg) of EEUHS for oral glucose tolerance and hypoglycemic test. The effects of EEUHS on body weight gain, urea, creatinine, cholesterol and hemoglobin concentration were also investigated.
 Result: The blood glucose concentrations of the EEUHS-treated groups were diminished (p < 0.05) relative to the diabetic control group. The urea, creatinine and cholesterol levels of the EEUHS-treated groups were lower (p < 0.05), but their hemoglobin concentrations were higher (p < 0.05) relative to the diabetic control group.
 Conclusion: The EEUHS elicits hypoglycemic effects and ameliorates complications of diabetes mellitus in streptozotocin-induced diabetic mice. This suggests that EEUHS can potentially be developed for the management of diabetic patients.
 
 
 

Preliminary Assessment of the Diversity and Habitat Preferences of Herpetofauna in Cholistan Desert, Pakistan

This one-year survey was conducted from February 2017 to January 2018 to assess the herpetofaunal diversity in Cholistan desert, Bahawalnagar district, Punjab, Pakistan. Field surveys were conducted during dawn and dusk for fifteen consecutive days in alternate months and five sub sampling sites were sampled at ten field visits. Specimens were collected through hand capture, using snake sticks, forceps, drag nets, noose traps, pitfall and funnel traps. Overall, two species of toads, two species of frogs, two species of turtles, ten lizards species and ten snake species belonging to 23 genera and 14 families were recorded. Simpson index was calculated as 0.933, evenness 0.733 and Shannon – Wiener index was 2.947 indicating moderate to high level of diversity. Bufo stomaticus (Pi = 0.1253), Uromastyx hardwickii (Pi = 0.0739) were the dominant amphibian and reptilian species, respectively while Uromastyx asmussi was recorded for the first time in the study area. Hand capture and pitfall traps appeared to be the most effective methods to capture the amphibian and reptiles. The distribution ranges of amphibians and reptiles have changed and such surveys are necessary to update baseline information in the country. We recommend further systematic survey work and molecular analysis of the native species be undertaken in the future to supplement our findings.

In vitro antidiabetic, anti-inflammatory and antioxidant potential of the ethanol extract of Uromastyx hardwickii skin

Purpose: To evaluate the in vitro antidiabetic, anti-inflammatory and antioxidant potential of the ethanol extract of Uromastyx hardwickii Skin (UHSEE).
 Methods: The in vitro effects of UHSEE at various concentrations (10 - 250 µg/mL) on the activities of ߙ-amylase, ߙ-glucosidase and glucose uptake by yeast cells were used to evaluate its antidiabetic potential. Nitric oxide (NO), 2,2-diphenyl-1-picrylhydrazyl (DPPH) and hydrogen peroxide inhibitory assay were employed to determine its antioxidant effects, while the anti-inflammatory effects were evaluated using human red blood cell (HRBC) membrane stabilization assay.
 Results: UHSEE inhibited ߙ-amylase and ߙ-glucosidase enzymes but increased glucose uptake by yeast cells in a concentration-dependent manner (p < 0.05). It also inhibited NO, DPPH, hydrogen peroxide and HRBC hemolysis in a concentration-dependent manner (p < 0.05).
 Conclusion: Uromastyx hardwickii skin exhibits promising good antidiabetic, antioxidant and antiinflammatory properties in vitro. However, its true potentials in this regard needs to be evaluted in vivo.

The use of fish and herptiles in traditional folk therapies in three districts of Chenab riverine area in Punjab, Pakistan

BackgroundLike botanical taxa, various species of animals are also used in traditional and modern health care systems. Present study was intended with the aim to document the traditional uses of herptile and fish species among the local communities in the vicinity of the River Chenab, Punjab Pakistan.MethodData collected by semi-structured interviews and questionnaires were subsequently analyzed using relative frequency of citation (FC), fidelity level (FL), relative popularity level (RPL), similarity index (SI), and rank order priority (ROP) indices.ResultsOut of total 81 reported species, ethnomedicinal uses of eight herptiles viz. Aspideretes gangeticus, A. hurum, Eublepharis macularius, Varanus bengalensis, Python molurus, Eryx johnii, Ptyas mucosus mucosus, Daboia russelii russelii and five fish species including Hypophthalmichthys molitrix, Cirrhinus reba, Labeo dero, Mastacembelus armatus, and Pethia ticto were reported for the first time from this region. Fat, flesh, brain, and skin were among the commonly utilized body parts to treat allergy, cardiovascular, nervous and respiratory disorders, sexual impotency, skin infections, and as antidote and anti-diabetic agents. Hoplobatrachus tigerinus, Duttaphrynus stomaticus, and Ptyas mucosus mucosus (herptiles), as well as Labeo rohita, Wallago attu, and Cirrhinus reba (fish) were top ranked with maximum informant reports, frequency of citations, and rank order priority. Uromastyx hardwickii, Ctenopharyngodon idella, H. molitrix, Cirrhinus mrigala, C. reba, L. rohita, L. calbasu, L. dero, and Pethia ticto were the species with 100% fidelity level. Furthermore, medicinal uses of Aspideretes gangeticus, Aspideretes hurum, Calotes versicolor, Daboia russelii russelii, Hypophthalmichthys molitrix, Cirrhinus reba, Labeo dero, Mastacembelus armatus, Pethia ticto, and Gagata cenia were reported for the first time.ConclusionAbout half of the reported species depicted zero similarity index with previously reported literature, which indicates strong associations of local inhabitants with animal species, particularly for therapeutic purpose. Inclusive studies on composition and bioactivities of the species with maximum use reports may contribute significantly in animal-based novel drugs discovery.

Population ecology of spiny tailed lizard (Saara hardwickii) from lesser Cholistan desert, Bahawalpur, Punjab

Current study was conducted to collect data on population ecology of spiny tailed lizard (Saara hardwickii) in lesser Cholistan desert, district Bahawalpur. The density of lizard recorded was based on the observations of selected habitats and on presence of active burrows. Adults (23%) were lower in the population followed by juveniles (35%) and sub-adults (42%) in number. Spiny tailed has territorial behavior and showed wide fluctuations with varying temperature. Lizards found to be agile in morning during hot season particularly during early hours of the day. During breeding season, lizards remain close to their burrows. They run quickly on the inappreciable disturbance from predators and back to their burrows while feeding. During study; it was observed that lizard eat its own shed skin to fulfill nutrient requirements. In various parts of the country including Cholistan, these lizards are frequently collected by illegal means and their fat and oil sold for medicine purpose. Poachers capture lizards and keep them in captivity by the brutal procedure of breaking the backbone. Detail study is required on ecology of spiny tailed lizard for its conservation in Cholistan desert; one of main area of its distribution in Pakistan. Keywords: Cholistan; Density; Ecology; Saara Hardwicke; Spiny lizard http://dx.doi.org/10.19045/bspab.2020.90149

Sandy ka tail (Saara Hardwickii Oil) and Footpath Hakeems: a Challenge to Modern Clinics

Penis enlargement, here and there called male improvement, alludes to a variety of methods planned to build the size, length, or erectile inflexibility of the human penis. Systems extend from manual activities to extending gadgets and surgical methods, with reports of triumphs and disappointments around the globe. As far back as the advancement of humanity, penis has been viewed as the most vital part of a male body which is in charge of proliferation. A solid and solid penis is coveted by each man. In the event that a man has an immature penis or on the off chance that it doesn't work legitimately while having intercourse the individual may fall into misery and despicable feeling about himself. Sanda (Saara hardwickii), commonly known as Hardwicke's spiny-tailed lizard or the Indian spiny-tailed lizard is a species of agamid lizard found patchily distributed in the Thar desert, Kutch, and surrounding arid zones in India and Pakistan.

Diversity and Habitat Preferences of Herpetofauna at Kalabagh Game Reserve, District Mianwali, Punjab, Pakistan

During present survey extending from July, 2015 through March, 2016 six amphibian species representing 6 genera and 3 families and 24 reptilian species representing 23 genera and 13 families, were recorded from Kalabagh Game Reserve, district Mianwali, Pakistan. Among the five capture techniques, i.e., hand picking, use of snake sticks, forceps, drag nets and noose traps, hand picking appeared the most effective one. The captured amphibian species included Bufo stomaticus, Microhyla ornata, Euphlyctis cyanophlyctis, Fejervarya limnocharis, Hoplobatrachus tigerinus, and Sphaeroteca breviceps. Single turtle species, Lissemys punctata andersoni was recorded from the study area. Among lizard species, Calotes versicolor, Laudakia nupta, Trapelus agilis pakistanensis, Eublepharis macularis, Cyrtopodion montiumsalsorum, Hemidactylus brookii, Hemidactylus flaviviridis, Ablepharus grayanus, Eutropis macularia, Lygosoma punctatum, Novoeumeces indothalensis, Uromastyx hardwickii, and Varanus bengalensis were recorded. Similarly, snake species included Leptotyphlops macrorhynchus, Ramphotyphlops braminus, Eryx johnii, Amphiesma stolatum, Platyceps rhodorachis, Lycodon aulicus, Ptyas mucosus, Bungarus caeruleus, Naja oxiana, and Echis carinatus. The venomous snake species of the study area included Naja oxiana, Bungarus caeruleus, and Echis carinatus.

Distribution and Current Status of the Reptiles of Khirthar Protected Area Complex (KPAC) and Adjoining Areas in Districts Karachi, Jamshoro and Thatta, Sindh, Pakistan

In this study, surveys were undertaken during 2008 – 2013, to record the distribution and status of reptiles of the area, during the study 41 species of reptiles were recorded. Twenty two important habitats for reptiles in the area were identified and listed. Indian Spiny-tailed Lizard (Saara hardwickii) was found to be under threat in its localized habitat in Jhimpir Wind Corridor block in Thatta district and Indian Fat–tail Gecko (Eublepharis macularius) was noted to have been almost disappeared from most of the area due to large scale capture of the species for sale in the local markets.

Planning agriculture based on landuse responses of threatened semiarid grassland species in India

Balancing biodiversity conservation and rural food security is a pressing challenge for developing countries, with tropical agro-grasslands facing particularly high human dependence and species’ endangerment. We explored the potential influences of agricultural growth and allocation of multiple landuses on the status of two threatened species inhabiting semiarid agro-grasslands of India. Sampling 1km2 cells for flagship lesser florican Sypheotides indica and 0.03ha plots for spiny-tailed lizard Saara hardwickii, we modeled species’ abundances with land-cover, vegetation structure, and disturbances using N-mixture (florican) and poisson (lizard) models. Florican abundance responded unimodally to herbaceous biomass (grassland proportion×ground-vegetation height), wherein, numbers peaked at optimally large combinations of grassland proportion (0.5–1) and ground-vegetation height (35–65cm). Whereas, lizard abundance was positively influenced by grassland occurrence and ground-vegetation<50cm cover but negatively influenced by cropland occurrence. Livestock grazing promoted short vegetation over tall vegetation, partially hindering florican but facilitating lizard. Such inter-specific differences in landuse response invoked multi-criteria planning based on surrogates of ecologically distinct species-groups. Fitting our models to simulated landuse scenarios, we demonstrated that managing florican habitats as grassland interspersed with croplands and pastures spared rotationally provided optimal results at low production-level. However, projected agricultural growth would cause considerable declines of florican (>30%) and lizard (>20%) populations. To prevent this, remaining florican occupied agro-grasslands should be secured as Community/Conservation reserves so that further landuse conversions can be legally restricted. Simultaneously, government schemes like food provisioning to small farmers through public distribution system could be harnessed to compensate for production deficit within/adjoining reserves.

Lactate Dehydrogenase Like Crystallin: A Potentially Protective Shield for Indian Spiny-Tailed Lizard (Uromastyx hardwickii) Lens Against Environmental Stress?

Taxon specific lens crystallins in vertebrates are either similar or identical with various metabolic enzymes. These bifunctional crystallins serve as structural protein in lens along with their catalytic role. In the present study, we have partially purified and characterized lens crystallin from Indian spiny-tailed lizard (Uromastyx hardwickii). We have found lactate dehydrogenase (LDH) activity in lens indicating presence of an enzyme crystallin with dual functions. Taxon specific lens crystallins are product of gene sharing or gene duplication phenomenon where a pre-existing enzyme is recruited as lens crystallin in addition to structural role. In lens, same gene adopts refractive role in lens without modification or loss of pre-existing function during gene sharing phenomenon. Apart from conventional role of structural protein, LDH activity containing crystallin in U. hardwickii lens is likely to have adaptive characteristics to offer protection against toxic effects of oxidative stress and ultraviolet light, hence justifying its recruitment. Taxon specific crystallins may serve as good models to understand structure-function relationship of these proteins.

Addiction to lizard: A rare case report.

Sir, Drug use and abuse is as old as mankind itself. Human beings have always had a desire to eat or drink substances that make them feel relaxed, stimulated, or euphoric. As time went by, “home remedies” were discovered and used to alleviate aches, pains and other ailments. Most of these were naturally occurring substances. No refinement had occurred and isolation of specific compounds (drugs) had not taken place. The use of various insects as substances of abuse is interesting and has not been reported in detail in medical literature. The Indian spiny tailed lizard (Uromastyx hardwickii) is found patchily distributed in the Thar desert, Kutch and surrounding arid zones in India and Pakistan. Since ancient times, these are hunted by the locals in the belief that the oil extracted from the fat of the lizard's body is an aphrodisiac and is used as an embrocation and as a cure for impotence.[1] We would like to illustrate a case report on lizard being used as a substance of abuse in a cannabis addict. A 25-year-old male prisoner, with a 15-year history of cannabis abuse, shifted his drug of abuse to lizards due to non-availability of cannabis in prison. He would burn lizards and take the charred remains and fill them in a bidi and inhale deeply. He claimed “instant high” on this substance equating it as pleasurable as cannabis. He was introduced to this practice of smoking lizard powder by other jail inmates who were drug addicts and due to non-availability of drugs, started abusing lizard powder. On his release from prison, he started using cannabis again and also continued the use of lizard powder by mixing it with cannabis (sulfa) and smoked it in a bidi. After a month of smoking this combination, he presented with an acute psychotic episode with grossly disorganized behavior and was admitted for the same. He was diagnosed with cannabis induced psychosis. His initial Brief Psychiatric Rating Scale score (BPRS) was 59 and he was treated with tablet risperidone 6 mg/day and benzodiazepines for sedation. His condition improved in a week, BPRS score was 30; but he continued to be apathetic, anergic and slothful. His attention and concentration were also impaired. There was also history of apathy, anergia and amotivation for the past few years. Past history and family history of any psychiatric disorder was negative. The diagnosis of comorbid amotivational syndrome was considered and patient was started on tablet dothiepin 75 mg/day. His symptoms improved and he was followed-up for 1 year during which he did not abuse any substance and his mental condition was normal. During adverse conditions due to non-availability of drugs or other substances of abuse, the man has found alternatives in the form of lizard powder, snake and scorpion venom and wasp sting.[2345] The psychoactive properties of lizard, which cause addiction are not known. Thus, future research should be directed at finding the root cause of this addiction and long term affects of such addictions.

Current Population Status of Diurnal Lizards of Karachi, Pakistan

Five districts of Karachi (East, West, South, Central and Malir) contain resident populations of lizards. During the present studies the current status of diurnal lizards of Karachi was investigated. The faunistic studies were based on seven species from three districts East, South and Malir of Karachi. 182 lizards were captured belonging to seven species, six genera and four families; Agamidae, Scincidae, Lacertidae and Varanidae. Among the 182 captured lizards were 56 Indian Garden Lizards, Calotes versicolor ; 20 Indian Spiny-tailed Lizards, Uromastyx hardwickii ; 72 Bronze Grass Skinks, Mabuya macularia ; 8 Striped Grass Skinks, Mabuya dissimilis ; 15 Indian Fringe-toad Sand Lizards, Acanthodactylus cantoris ; 10 Long-tailed Desert Lacertas, Mesalina watsonana , and 1 Indian Monitor Varanus bengalensis . The results of the present study indicate that the current status of diurnal lizards, i.e., Indian Garden Lizard ( Calotes versicolor ), Bronze Grass Skink ( Mabuya macularia ), Striped Grass Skink ( Mabuya dissimilis ), Indian Fringe-toad sand Lizard ( Acanthodactylus cantoris ), and Long-tailed Desert Lacerta ( Mesalina watsonana ) are common in three selected districts of Karachi, while the Indian Spiny-tailed Lizard ( Uromastyx hardwickii ) and Indian Monitor lizard ( Varanus bengalensis ) have been recorded as threatened species. Uromastyx hardwickii is an endangered species and is already included in the IUCN Red List and CITES Appendix. Internationally, 25% of reptiles are listed as threatened (IUCN, 2002). In Pakistan some lizard species are threatened. Present studies also recorded Uromastyx hardwickii and Varanus bengalensis as threatened species in the three districts of Karachi. The Brilliant Agama ( Trapelus agilis isolepis ) was not found in the three districts of Karachi. Either it is threatened or has gone extinct or has been shifted to other habitats due to destruction of habitat and increase of human population.

Ecological observations on the Indian Spiny-tailed Lizard Saara hardwickii (Gray, 1827) (Reptilia: Squamata: Agamidae) in Tal Chhapar Wildlife Sanctuary, Rajasthan, India

Observations on the Indian Spiny-tailed Lizard Saara hardwickii (Gray, 1827) were undertaken in Tal Chhapar Wildlife Sanctuary, Rajasthan, India during the monsoons (July) following quadrat sampling that was time-constrained. The study revealed that the area is one of the preferable habitats for the species. A population analysis showed that the relative abundance of the subadults was higher, followed by juveniles and adults during the study period. The beginning of activity of the lizards was found to vary over the study period depending on prevailing weather conditions. The activity pattern was bimodal, except across rain events. The study revealed two important ecological findings about these lizards; complete sealing of burrow during rains which differed from partial sealing on normal days and complete diurnal cycle of body colour changes during the monsoon. Feeding was the predominant activity of this lizard followed by basking, resting and chasing each other. The adult lizards were found to be strictly herbivorous, in spite of an abundance of insects available in the area during the period. Subadults and juveniles were found to eat both plant parts, as well as insects. Microhabitat use such as inside grass clumps was found to be higher followed by barren ground, under shade and on stones.

Food habits of the Indian fox ( Vulpes bengalensis) in Kutch, Gujarat, India

We characterized the diet of the Indian fox ( Vulpes bengalensis) during the breeding season in a semi-desert region of Western India. Diet was estimated using scat analysis. We used Index of Relative Importance (IRI) to determine the contribution of prey items in the diet of the Indian fox. Indian foxes were observed to feed on a wide variety of prey items. Arthropods were the most frequently occurring prey in their diet. IRI scores were highest for the group Coleoptera and Orthoptera followed by rodents, termites, Ziziphus fruits and spiny tailed lizards ( Uromastyx hardwickii). IRI scores for rodents were higher for pups, differing significantly from proportions present in adult diet, thus indicating that they are crucial food items for the young ones. Prey proportions in the fox diet differed between the two habitats in the study area (grassland and scrubland). Our data suggest that the Indian fox is essentially an omnivore showing similar diet (in terms of high incidence of arthropods) to foxes inhabiting arid and semi-arid regions. The opportunistic and generalist strategy has probably helped the species to survive in varied habitats across the Indian subcontinent.

Biomechanical assessment of evolutionary changes in the lepidosaurian skull.

The lepidosaurian skull has long been of interest to functional morphologists and evolutionary biologists. Patterns of bone loss and gain, particularly in relation to bars and fenestrae, have led to a variety of hypotheses concerning skull use and kinesis. Of these, one of the most enduring relates to the absence of the lower temporal bar in squamates and the acquisition of streptostyly. We performed a series of computer modeling studies on the skull of Uromastyx hardwickii, an akinetic herbivorous lizard. Multibody dynamic analysis (MDA) was conducted to predict the forces acting on the skull, and the results were transferred to a finite element analysis (FEA) to estimate the pattern of stress distribution. In the FEA, we applied the MDA result to a series of models based on the Uromastyx skull to represent different skull configurations within past and present members of the Lepidosauria. In this comparative study, we found that streptostyly can reduce the joint forces acting on the skull, but loss of the bony attachment between the quadrate and pterygoid decreases skull robusticity. Development of a lower temporal bar apparently provided additional support for an immobile quadrate that could become highly stressed during forceful biting.

Combined finite element and multibody dynamics analysis of biting in a Uromastyx hardwickii lizard skull.

Lizard skulls vary greatly in shape and construction, and radical changes in skull form during evolution have made this an intriguing subject of research. The mechanics of feeding have surely been affected by this change in skull form, but whether this is the driving force behind the change is the underlying question that we are aiming to address in a programme of research. Here we have implemented a combined finite element analysis (FEA) and multibody dynamics analysis (MDA) to assess skull biomechanics during biting. A skull of Uromastyx hardwickii was assessed in the present study, where loading data (such as muscle force, bite force and joint reaction) for a biting cycle were obtained from an MDA and applied to load a finite element model. Fifty load steps corresponding to bilateral biting towards the front, middle and back of the dentition were implemented. Our results show the importance of performing MDA as a preliminary step to FEA, and provide an insight into the variation of stress during biting. Our findings show that higher stress occurs in regions where cranial sutures are located in functioning skulls, and as such support the hypothesis that sutures may play a pivotal role in relieving stress and producing a more uniform pattern of stress distribution across the skull. Additionally, we demonstrate how varying bite point affects stress distributions and relate stress distributions to the evolution of metakinesis in the amniote skull.

Rigid-body analysis of a lizard skull: Modelling the skull of Uromastyx hardwickii

Lizard skulls vary greatly in their detailed morphology. Theoretical models and practical studies have posited a definite relationship between skull morphology and bite performance, but this can be difficult to demonstrate in vivo. Computer modelling provides an alternative approach, as long as hard and soft tissue components can be integrated and the model can be validated. An anatomically accurate three-dimensional computer model of an Uromastyx hardwickii skull was developed for rigid-body dynamic analysis. The Uromastyx jaw was first opened under motion control, and then muscle forces were applied to produce biting simulations where bite forces and joint forces were calculated. Bite forces comparable to those reported in the literature were predicted, and detailed muscular force information was produced along with additional information on the stabilizing role of temporal ligaments in late jaw closing.