The hunt for the missing fish
Tiktaalik is a lobe-finned fish that lived during the late Devonian period (around 375 million years ago) and the first fossils were found in 2004 on Ellesmere Island in Nunavut, Canada. The discovery, made by Edward B. Daeschler of the Academy of Natural Sciences, Neil H. Shubin from the University of Chicago, and Harvard University Professor Farish A. Jenkins Jr, was published in the April 6, 2006, issue of Nature
The name Tiktaalik is an Inuktitut word meaning "large freshwater fish" this name was given by Inuit elders of Canada's Nunavut Territory, where the fossil was discovered.
When Tiktaalik was alive it would have lived on the continent of Laurentia, this was the continent of North America but also included Greenland and was centered on the equator and had a warm climate. The fossils were found in the deposits of meandering stream systems suggesting a benthic animal that lived on the bottom of shallow waters and perhaps even out of the water for short periods, with a skeleton indicating that it could support its body under the force of gravity whether in very shallow water or on land.
Credit to Pelvic girdle and fin of Tiktaalik roseae by Neil H. Shubin, Edward B. Daeschler, and Farish A. Jenkins Jr.
Tiktaalik is a strange fish, strange in the sense that it had gills and scales like any other fish but it also strong interior bones in its fins. This allowed for both paddling and also allowed Tiktaalik to prop himself up in shallow water and even pull himself up on the land. The front arms of Tiktaalik could be more described as more like that of a crocodile, including a shoulder, elbow, and wrist.
On the top of the skull there were opening that indicated Tiktaalik had primitive lungs as well as gills. This attribute would have been useful in shallow water, where higher water temperature would lower oxygen content. This development may have led to the evolution of a more robust ribcage, a key evolutionary trait of land-living creatures. The more robust ribcage of Tiktaalik would have helped support the animal's body any time it ventured outside a fully aquatic habitat.
At the time Tiktaalik was swimming about, the first trees had started growing on land and would have started to shed their leaves into the muddy water, attracting small prey into warm oxygen-poor shallows that were difficult for larger fish to swim in.
Why did Tiktaalik go onto land
The rivers in the Devonian were a competition for survival, there were many choices for body plans, you could be big to not be eaten or small to get away from predators, grow massive teeth bite other fish or grow thick scales to be hard to bite but Tiktaalik managed to get away from the large fish and eat the small fish by crawling on the mud flats.
First, it was a convenient way to escape the huge carnivorous fish that lived in the deeper waters. It also probably helped Tiktaalik, who was a predator as well, pursue some of the smaller fish hiding in the shallows and the bug-like critters inhabiting the dense foliage banking the rivers and streams.
- https://tiktaalik.uchicago.edu/meetTik3.html
Thank you for reading this far down i hope you enjoy, I will be doing weekly posts again, I would really appreciate if you could reblog this thank you <3
