''Amygdalodon'' (; "

almond The almond (''Prunus amygdalus'', Synonym (taxonomy)#Botany, syn. ''Prunus dulcis'') is a species of tree from the genus ''Prunus''. Along with the peach, it is classified in the subgenus ''Amygdalus'', distinguished from the other subgenera ...

tooth" for its almond shaped teeth) was a

genus Genus (; : genera ) is a taxonomic rank above species and below family (taxonomy), family as used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In bino ...

of basal

sauropod Sauropoda (), whose members are known as sauropods (; from '' sauro-'' + '' -pod'', 'lizard-footed'), is a clade of saurischian ('lizard-hipped') dinosaurs. Sauropods had very long necks, long tails, small heads (relative to the rest of their b ...

from the Middle Jurassic of Argentina. The type species is ''Amygdalodon patagonicus''. Fossils of ''Amygdalodon'' have been found in the

Toarcian The Toarcian is, in the International Commission on Stratigraphy, ICS' geologic timescale, an age (geology), age and stage (stratigraphy), stage in the Early Jurassic, Early or Lower Jurassic. It spans the time between 184.2 Megaannum, Ma (million ...

Cerro Carnerero Formation The Cerro Carnerero Formation is a geological formation of the Golfo San Jorge Basin in Chubut Province, Patagonia, Argentina.Jurassic The Jurassic ( ) is a Geological period, geologic period and System (stratigraphy), stratigraphic system that spanned from the end of the Triassic Period million years ago (Mya) to the beginning of the Cretaceous Period, approximately 143.1 Mya. ...

(about 180-172 million years ago). Very little is known about it, but it is one of the few Jurassic dinosaurs from South America found thus far.

Discovery

Type material of Amygdalodon patagonicus MLP 46-VII1-21-1 19

The holotype (MLP 46-VIII-21-1) consists of some vertebrae, ribs, four complete and three partial teeth, and a partial pelvis and shoulder-blade, of which was discovered in 1936. The

type species In International_Code_of_Zoological_Nomenclature, zoological nomenclature, a type species (''species typica'') is the species name with which the name of a genus or subgenus is considered to be permanently taxonomically associated, i.e., the spe ...

, ''Amygdalodon patagonicus'', was described by Cabrera in

Argentina Argentina, officially the Argentine Republic, is a country in the southern half of South America. It covers an area of , making it the List of South American countries by area, second-largest country in South America after Brazil, the fourt ...

in 1947.A. Cabrera. 1947. Un saurópodo nuevo del Jurásico de Patagonia. Instituto del Museo de la Universidad Nacional de La Plata, ''Notas del Museo de La Plata, Paleontología'' 12(95):1–17 Until 1936 sauropod fossils from Argentina were completely unknown then, prompted by Piatnitzky's brief mention of "bones of a saurian of no less than 5-7m long", Dr. Tomás Suero took a trip to

Chubut Chubut may refer to: * Chubut Province Chubut ( from Tehuelche language, Tehuelche 'transparent'; ) is a provinces of Argentina, province in southern Argentina, situated between the 42nd parallel south (the border with Río Negro Province), ...

to check out deposits overlying the Liassic of the Pampa de Agnia and discovered the remains of a Jurassic sauropod dinosaur around twice the size of Piatnitzky's estimation (in 1936).

Size

''Amygdalodon'' is estimated to have been long and tall. This

quadruped Quadrupedalism is a form of locomotion in which animals have four legs that are used to bear weight and move around. An animal or machine that usually maintains a four-legged posture and moves using all four legs is said to be a quadruped (fr ...

al dinosaur had an estimated weight of over .

Classification

Rauhut (2003) placed ''Amygdalodon'' as Eusauropoda ''incertae sedis'' based on examination of the type material. Later, a cladistic analysis conducted by Carballido et al. (2010) recovered the genus as a non-eusauropod sauropod. Holwerda and Pol (2018) concurred, recovering ''Amygdalodon'' as sister to ''

Isanosaurus ''Isanosaurus'' ("North-eastern Thailand lizard") is an extinct genus of sauropod dinosaur from Thailand. It was originally dated to approximately 219-199 Mya (unit), million years ago during the Late Triassic (late Norian to Rhaetian stage ...

''.Femke M. Holwerda & Diego Pol (2018). Phylogenetic analysis of Gondwanan basal eusauropods from the Early-Middle Jurassic of Patagonia, Argentina. Spanish Journal of Palaeontology 33(2): 289-298. DOI: 10.7203/sjp.33.2.13604 https://www.researchgate.net/publication/330520139_Phylogenetic_analysis_of_Gondwanan_basal_eusauropods_from_the_Early Middle_Jurassic_of_Patagonia_Argentina A basal sauropod classification for ''Amygdalodon'' was supported by Pol and colleagues in 2022, with it showing the first signs of dental modification for bulk feeding that is retained in later sauropods, but it does not have the vertebral features found in more derived sauropods. They found it in a polytomy with the Asian taxon ''

Gongxianosaurus ''Gongxianosaurus'' is a genus of basal sauropod dinosaur from the early Jurassic Period (Sinemurian- Pliensbachian stage). The only species is ''Gongxianosaurus shibeiensis''. Based on four fragmentary to complete specimens found in the Zil ...

'', and possibly related to South American ''

Volkheimeria ''Volkheimeria'' is an extinct genus of sauropod dinosaurs that lived in what is now Argentina during the Early Jurassic, 178–179 million years ago. Its type and only species is ''Volkheimeria chubutensis''. Discovery and naming The only k ...

'', though the latter had a very labile position.

References

External links

DinoDictionary
{{Taxonbar, from=Q133524 Sauropoda Dinosaur genera Toarcian dinosaurs Dinosaurs of Argentina Fossil taxa described in 1947 Taxa named by Ángel Cabrera