Manidens

Superregnum: Eukaryota
Cladus: Unikonta
Cladus: Opisthokonta
Cladus: Holozoa
Regnum: Animalia
Subregnum: Eumetazoa
Cladus: Bilateria
Cladus: Nephrozoa
Superphylum: Deuterostomia
Phylum: Chordata
Subphylum: Vertebrata
Infraphylum: Gnathostomata
Megaclassis: Osteichthyes
Cladus: Sarcopterygii
Cladus: Rhipidistia
Cladus: Tetrapodomorpha
Cladus: Eotetrapodiformes
Cladus: Elpistostegalia
Superclassis: Tetrapoda
Cladus: Reptiliomorpha
Cladus: Amniota
Classis: Reptilia
Cladus: Eureptilia
Cladus: Romeriida
Subclassis: Diapsida
Cladus: Sauria
Infraclassis: Archosauromorpha
Cladus: Crurotarsi
Divisio: Archosauria
Cladus: Avemetatarsalia
Cladus: Ornithodira
Subtaxon: Dinosauromorpha
Cladus: Dinosauriformes
Cladus: Dracohors
Cladus: Dinosauria
Ordo: †Ornithischia

Familia: †Heterodontosauridae
Genus: †Manidens
Species: †M. condorensis
Name

†Manidens Pol, Rauhut & Becerra, 2011

Type species: †Manidens condorensis Pol, Rauhut & Becerra, 2011
References

Pol, D.; Rauhut, O.W.M.; Becerra, M. 2011. A Middle Jurassic heterodontosaurid dinosaur from Patagonia and the evolution of heterodontosaurids. Naturwissenschaften 98 (5): 369–379. DOI: 10.1007/s00114-011-0780-5

Manidens is an extinct genus of heterodontosaurid dinosaur from the Early Jurassic of Patagonia. It is a sister taxon of the closesly related Pegomastax from South Africa.[2] Fossils have been found in the Cañadón Asfalto Formation in Chubut Province, Argentina, dating to the Bajocian.[3]
Etymology

The type species of Manidens, Manidens condorensis, was described in the journal Naturwissenschaften in 2011. Manidens was named in by Diego Pol, Oliver Rauhut and Marcos Becerra. The generic name is derived from Latin manus, "hand", and dens, "tooth", a reference to the hand-shaped form of the posterior lower teeth. The specific name refers to the village of Cerro Cóndor, located near to the Queso Rallado site where the specimen was found by zoologist Guillermo Rougier.[3]
Description

The holotype specimen of Manidens, MPEF-PV 3211, consists of a partial skeleton with a skull and lower jaw, including the axial column except most of the tail; a left shoulder girdle; and the pelvis. The specimens MPEF-PV 1719, 1786, 1718, 3810, 3811, isolated posterior teeth, from the same locality and horizon as the holotype specimen are also referred to this genus.[4] The specimens were found in the Queso Rallado locality of the Cañadón Asfalto Formation, dating originally to the Aalenian–Early Bathonian stages, 171 ± 5 to 167 ± 4 Ma, yet where latter constrained to 179-178 million years, that is Middle-Late Toarcian.[5]

Manidens was a relatively basal heterodontosaurid that grew to about 60 cm (2.0 ft) in length and 500 g (18 oz) in body mass, smaller than later heterodontosaurids.[6] It has high-crowned teeth indicative of an increased adaptation to a herbivorous diet but lacks the wear facets seen in more advanced forms like Heterodontosaurus. Manidens is the sister taxon of a clade consisting of the African species Heterodontosaurus, Abrictosaurus and Lycorhinus, indicating an early radiation of the heterodontosaurids.[3] The discovery of filamentous integumentary structures in the related Tianyulong suggests that they may also have been present in other heterodontosaurids such as Manidens.[7]
Life restoration

Tooth replacement was asynchronous in Manidens, which exhibited dental replacement in a continuous anterior-to-posterior wave pattern. Furthermore, Manidens represents the first known occurrence of a heterodontosaurid with dental replacement of its caniniform teeth, which may have had distinct timing relative to its cheek dentition.[8]
Phylogeny

Cladogram after Pol et al., 2011:[3]

Ornithischia	Pisanosaurus Echinodon* Heterodontosauridae Tianyulong Fruitadens Manidens Abrictosaurus BMNH A100 Heterodontosaurus Lycorhinus Eocursor Genasauria

*Note: Pol et al. regard Echinodon as a genus of Heterodontosauridae.
Paleoecology

Fossils attributed to Manidens from Argentina indicate that this dinosaur may have been at least partially arboreal. The specimens consists of a series of bones from both hind feet and a few tail vertebrae, and are tentatively attributed to Manidens on the basis of provenance. The long toe bones indicate that the toe bones were capable of grasping; distinct anchor attachments for the muscles and tendons of the hallux indicate that its hallux was smaller than the rest of the toes but could still have grasped. Principal component analysis found that the feet of Manidens were most similar to those of tree-perching birds.[9]
References

Fantasia, A.; Föllmi, K. B.; Adatte, T.; Spangenberg, J. E.; Schoene, B.; Barker, R. T.; Scasso, R. A. (2021). "Late Toarcian continental palaeoenvironmental conditions: An example from the Canadon Asfalto Formation in southern Argentina". Gondwana Research. 89 (1): 47–65. doi:10.1016/j.gr.2020.10.001. S2CID 225120452. Retrieved 27 August 2021.
Sereno, Paul C. (3 October 2012). "Taxonomy, morphology, masticatory function and phylogeny of heterodontosaurid dinosaurs". ZooKeys (223): 1–225. doi:10.3897/zookeys.223.2840. PMC 3491919. PMID 23166462.
Pol, D.; Rauhut, O.W.M.; Becerra, M. (2011). "A Middle Jurassic heterodontosaurid dinosaur from Patagonia and the evolution of heterodontosaurids". Naturwissenschaften. 98 (5): 369–379. Bibcode:2011NW.....98..369P. doi:10.1007/s00114-011-0780-5. PMID 21452054. S2CID 22636871.
Becerra, Marcos G.; Pol, Diego; Marsicano, Claudia; Rauhut, Oliver (22 May 2013). "The dentition of Manidens condorensis (Ornithischia; Heterodontosauridae) from the Jurassic Cañadón Asfalto Formation of Patagonia: morphology, heterodonty and the use of statistical methods for identifying isolated teeth". Historical Biology. 26 (4): 480–492. doi:10.1080/08912963.2013.794227. S2CID 84862489.
Pol, D.; Gomez, K.; Holwerda, F. M.; Rauhut, O. W.; Carballido, J. L. (2022). "Sauropods from the Early Jurassic of South America and the Radiation of Eusauropoda". South American Sauropodomorph Dinosaurs. 1 (1): 131–163. doi:10.1007/978-3-030-95959-3_4. Retrieved 2 May 2022.
Paul, G. S. (2016). The Princeton Field Guide to Dinosaurs (2nd ed.). Princeton, New Jersey: Princeton University Press. p. 267. ISBN 9780691167664.
Zheng, Xiao-Ting; You, Hai-Lu; Xu, Xing; Dong, Zhi-Ming (19 March 2009). "An Early Cretaceous heterodontosaurid dinosaur with filamentous integumentary structures". Nature. 458 (7236): 333–336. Bibcode:2009Natur.458..333Z. doi:10.1038/nature07856. PMID 19295609. S2CID 4423110.
Becerra, Marcos G.; Pol, Diego; Whitlock, John A.; Porro, Laura B. (29 September 2020). "Tooth replacement in Manidens condorensis: baseline study to address the replacement pattern in dentitions of early ornithischians". Papers in Palaeontology. 7 (2): 1167–1193. doi:10.1002/spp2.1337. hdl:11336/143687. S2CID 224937914.
Becerra, M.C.; Pol, D.; Rauhut, O.W.M.; Cerda, I.A. (2016). "New heterodontosaurid remains from the Cañadón Asfalto Formation: cursoriality and the functional importance of the pes in small heterodontosaurids". Journal of Paleontology. 90 (3): 555–577. doi:10.1017/jpa.2016.24. S2CID 56436933.