Pronunciation: uh-MIG-duh-loh-don
Meaning: Almond tooth
Author/s: Cabrera (1947)
Synonyms: None known
First Discovery: Chubut, Argentina
Discovery Chart Position: #185
Amygdalodon patagonicus
Until 1936, sauropod fossils from Argentina were completely unknown. Then, prompted by Alejandro 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.
The area yielded the fragmentary remains from two or possibly three individuals of the same species, including vertebrae, ribs, a partial pelvis, something thought to resemble a shoulder blade which probably isn't and, most importantly, a handful of almond-shaped teeth for which Amygdalodon was named. However, just like Vulcanodon, this dinosaur's name-prompting teeth no longer belong to this dinosaur. And then they did again.
When Oliver Rauhut revisited Amygdalodon in 2003, six of the original seven broad-for-a-eusauropod chompers had mysteriously vanished, so, in a stroke of brilliance, he ensured this dinosaur's validity by assigning a distinct back vertebra as lectotype and nullified any chance of another dodgy, single tooth-based taxon. Funnily enough, though, Carballido and Pol found all but one of the missing teeth in 2010 for a redescription and photo shoot, and with their oval-ish shape and wrinkled enamel, they really do look like almonds.
Valid as it may be, not a lot is known of Amygdalodon. Much-mooted estimates of fifteen meters in length, four meters in height, and 24 tons in weight are probably way too high. But, for sure, Amygdalodon is the first Middle Jurassic sauropod to be discovered in Argentina, the earliest known eusauropod (true sauropod) from the whole of South America, and one of only a few dinosaurs of any kind that are currently known from this time and place.
The area yielded the fragmentary remains from two or possibly three individuals of the same species, including vertebrae, ribs, a partial pelvis, something thought to resemble a shoulder blade which probably isn't and, most importantly, a handful of almond-shaped teeth for which Amygdalodon was named. However, just like Vulcanodon, this dinosaur's name-prompting teeth no longer belong to this dinosaur. And then they did again.
When Oliver Rauhut revisited Amygdalodon in 2003, six of the original seven broad-for-a-eusauropod chompers had mysteriously vanished, so, in a stroke of brilliance, he ensured this dinosaur's validity by assigning a distinct back vertebra as lectotype and nullified any chance of another dodgy, single tooth-based taxon. Funnily enough, though, Carballido and Pol found all but one of the missing teeth in 2010 for a redescription and photo shoot, and with their oval-ish shape and wrinkled enamel, they really do look like almonds.
Valid as it may be, not a lot is known of Amygdalodon. Much-mooted estimates of fifteen meters in length, four meters in height, and 24 tons in weight are probably way too high. But, for sure, Amygdalodon is the first Middle Jurassic sauropod to be discovered in Argentina, the earliest known eusauropod (true sauropod) from the whole of South America, and one of only a few dinosaurs of any kind that are currently known from this time and place.
[Almond Tooth of Patagonia]Etymology
Amygdalodon is derived from the Greek "amygdalos" (almond) and "dont" (tooth), in reference to its (suprise!) almond shaped teeth. The species epithet, patagonicus (pat-uh-GON-ih-kus), refers to Patagonia, the region of Argentina where it was found.
Discovery
The remains of Amygdalodon were found in the Cerro Carnerero Formation, on the eastern slope of Sierra Pampa de Agnia, some 8 km west-southwest of the García Prieto ranch (formerly the Gallina ranch), Chubut Province, Patagonia, Argentina, by Alejandro Matveievich Piatnitzky in 1936.
The original holotype (MLP 46-VIII-21-1), comprising several vertebrae (one neck, two back and two tail), a few neck and back ribs, four complete and three partial teeth, a partial pelvic bone, and what Cabrera identified as a fragment of shoulder blade, was excavated by Dr. Tómas Suero in 1947.
Another back vertebra, a partial hip vertebra, and a piece of shin (MLP 36-XI-10-3), collected from the same locality by Piatnitzky prior to Suero’s excavation, were referred to Amygdalodon by Casamiquela in 1963. The size difference between this material and the fossils described by Suero, suggests at least two individuals were present.
From the holotype material, Oliver Rauhut designated one of the back vertebrae as the lectotype (MLP 46-VIII-21-1/2) in 2003.
