Post by Life on Feb 23, 2021 21:49:29 GMT 5
Classification
*Also highlighted as such in Sander et al (2011):
Citation: Sander, P. M., Chen, X., Cheng, L., & Wang, X. (2011). Short-snouted toothless ichthyosaur from China suggests Late Triassic diversification of suction feeding ichthyosaurs. PLoS One, 6(5), e19480.
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RELATED:
Ichthyosaurs reference thread
Shonisaurus sikanniensis discussion thread
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Shonisaurus sikanniensis: Unearthing a Triassic Giant
SEPTEMBER 16, 2019 / ROYAL TYRRELL MUSEUM OF PALAEONTOLOGY
Ichthyosaurs were fully aquatic marine reptiles with dolphin-like bodies. Most were small fish-eaters, but some reached the size of whales. They first appeared about 245 million years ago at the beginning of the Mesozoic Era (the Age of Dinosaurs), and died out about 100 million years ago.
Illustration of a group of ichthyosaurs.
Shonisaurus sikanniensis is the world’s largest-known marine reptile. This incredible specimen is 220 million years old. At 21 metres, it is 30 percent larger than any previously known ichthyosaur. It took Royal Tyrrell Museum crews, led by the late Dr. Elizabeth Nicholls, three summers to excavate this specimen from its remote location in northeastern British Columbia.
Shonisaurus sikanniensis on display at the Royal Tyrrell Museum.
The excavation of Shonisaurus sikanniensis began five years after its initial discovery in 1992. Removing the remains of the specimen presented many logistical obstacles. Just getting to the remote location along the banks of the Sikanni Chief River near Pink Mountain, B.C. was a challenge.
The rock surrounding the specimen was very hard. Heavy equipment like jackhammers, compressors, and rock saws needed for the excavation were transported to the site by helicopter. After mapping the specimen, the natural cracks in the rock were used to separate the skeleton into blocks.
The late Dr. Elizabeth (Betsy) Nicholls (the Royal Tyrrell Museum’s former Curator of Marine Reptiles) at the excavation site.
The largest block containing the skull weighed four and a half tonnes. Fortunately, the helicopter used to transport the skull block had a maximum allowance of five tonnes. Once all the blocks were removed from the site, they were loaded onto a trailer and transported 1200 km to the Museum.
Preparation of the skeleton of Shonisaurus sikanniensis took over four years to complete. The rock was removed from the surface of the bone using an air scribe—a vibrating power tool used to chip away at the surrounding matrix. The skull was prepared on both sides while the rest of the skeleton was prepared on just one side.
This specimen was a gigantic mystery, prompting scientific curiosity regarding its size, behaviours, mobility, relatives, and feeding habits. Lacking teeth, scientists determined it was the earliest-known example of a giant filter-feeding vertebrate. There is still much more to be learned about this fascinating animal.
LINK: royaltyrrellmuseum.wpcomstaging.com/2019/09/16/shonisaurus-sikanniensis-unearthing-a-triassic-giant/
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| Kingdom | Animalia | |
| Phylum | Chordata | |
| Subphylum | Vertebrata | |
| Class | Reptilia | |
| Order | Ichthyosauria | Blainville, 1835 |
| Clade | Merriamosauria | Motani, 1999 |
| Family | Shastasauridae | Merriam, 1902 |
| Genus | Shonisaurus | Camp, 1976 |
| Species | Shonisaurus sikanniensis | Nicholls and Manabe, 2004; see 2nd post below |
| Holotype specimen | TMP 1994.378.02 (estimated TL = 21 m) | Nicholls and Manabe, 2004; see 2nd post below |
| Geological Period and Location | The Norian Late Triassic; British Columbia | Nicholls and Manabe, 2004; see 2nd post below |
| Feeding mechanism | Edentulous; Suction feeding* | Nicholls and Manabe, 2004; see 2nd post below |
*Also highlighted as such in Sander et al (2011):
In fact, “suction feeding is the dominant method of prey capture in aquatic vertebrates” [11, p. 1415] but has not been postulated for Mesozoic marine reptiles with the exception of the giant Shonisaurus sikanniensis [13]. - Sander et al (2011)
Citation: Sander, P. M., Chen, X., Cheng, L., & Wang, X. (2011). Short-snouted toothless ichthyosaur from China suggests Late Triassic diversification of suction feeding ichthyosaurs. PLoS One, 6(5), e19480.
---
RELATED:
Ichthyosaurs reference thread
Shonisaurus sikanniensis discussion thread
-----
Shonisaurus sikanniensis: Unearthing a Triassic Giant
SEPTEMBER 16, 2019 / ROYAL TYRRELL MUSEUM OF PALAEONTOLOGY
Ichthyosaurs were fully aquatic marine reptiles with dolphin-like bodies. Most were small fish-eaters, but some reached the size of whales. They first appeared about 245 million years ago at the beginning of the Mesozoic Era (the Age of Dinosaurs), and died out about 100 million years ago.
Illustration of a group of ichthyosaurs.
Shonisaurus sikanniensis is the world’s largest-known marine reptile. This incredible specimen is 220 million years old. At 21 metres, it is 30 percent larger than any previously known ichthyosaur. It took Royal Tyrrell Museum crews, led by the late Dr. Elizabeth Nicholls, three summers to excavate this specimen from its remote location in northeastern British Columbia.
Shonisaurus sikanniensis on display at the Royal Tyrrell Museum.
The excavation of Shonisaurus sikanniensis began five years after its initial discovery in 1992. Removing the remains of the specimen presented many logistical obstacles. Just getting to the remote location along the banks of the Sikanni Chief River near Pink Mountain, B.C. was a challenge.
The rock surrounding the specimen was very hard. Heavy equipment like jackhammers, compressors, and rock saws needed for the excavation were transported to the site by helicopter. After mapping the specimen, the natural cracks in the rock were used to separate the skeleton into blocks.
The late Dr. Elizabeth (Betsy) Nicholls (the Royal Tyrrell Museum’s former Curator of Marine Reptiles) at the excavation site.
The largest block containing the skull weighed four and a half tonnes. Fortunately, the helicopter used to transport the skull block had a maximum allowance of five tonnes. Once all the blocks were removed from the site, they were loaded onto a trailer and transported 1200 km to the Museum.
Preparation of the skeleton of Shonisaurus sikanniensis took over four years to complete. The rock was removed from the surface of the bone using an air scribe—a vibrating power tool used to chip away at the surrounding matrix. The skull was prepared on both sides while the rest of the skeleton was prepared on just one side.
This specimen was a gigantic mystery, prompting scientific curiosity regarding its size, behaviours, mobility, relatives, and feeding habits. Lacking teeth, scientists determined it was the earliest-known example of a giant filter-feeding vertebrate. There is still much more to be learned about this fascinating animal.
LINK: royaltyrrellmuseum.wpcomstaging.com/2019/09/16/shonisaurus-sikanniensis-unearthing-a-triassic-giant/
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