''Amygdalodon'' (; "

almond The almond (''Prunus amygdalus'', syn. ''Prunus dulcis'') is a species of tree native to Iran and surrounding countries, including the Levant. The almond is also the name of the edible and widely cultivated seed of this tree. Within the genus ...

tooth" for its almond shaped teeth) was a

genus Genus ( plural genera ) is a taxonomic rank used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In the hierarchy of biological classification, genus com ...

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 bo ...

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 ICS' geologic timescale, an age and stage in the Early or Lower Jurassic. It spans the time between 182.7 Ma (million years ago) and 174.1 Ma. It follows the Pliensbachian and is followed by the Aalenian. The Toarcian ...

Cerro Carnerero Formation The Cerro Carnerero Formation is a geological formation of the Golfo San Jorge Basin in Chubut Province, Patagonia, Argentina.

of the

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 Mya. The J ...

(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

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 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 species that contains the biological type specimen ...

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

Argentina Argentina (), officially the Argentine Republic ( es, link=no, República Argentina), is a country in the southern half of South America. Argentina covers an area of , making it the second-largest country in South America after Brazil, th ...

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 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 where four limbs are used to bear weight and move around. An animal or machine that usually maintains a four-legged posture and moves using all four limbs is said to be a quadruped (from Latin ''quattuor' ...

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'' means "North-eastern thailand lizard" was a sauropod dinosaur from Thailand. It was originally dated to approximately 210 million years ago during the Late Triassic (late Norian to Rhaetian stages), which would make it on ...

''.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 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 (Toarcian stage). The only species is ''Gongxianosaurus shibeiensis''. Based on four fragmentary to complete specimens found in China (Sichuan Province), ...

'', 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 kn ...

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

References

External links

DinoDictionary
{{Taxonbar, from=Q133524 Sauropods Dinosaur genera Toarcian life Middle Jurassic dinosaurs of South America Jurassic Argentina Fossils of Argentina Golfo San Jorge Basin Fossil taxa described in 1947 Taxa named by Ángel Cabrera