I have searched and searched for this answer but I had no luck. Then i read that the families from my last post died off in the cretaceous era, about 65 million years ago. So by looking at that era I read about the mass extinction at the end of the cretaceous era.
This mass extinction killed off many families of land animals/plants and more then half of all the marine species. This got me thinking about what might have happened to the vampire squid's relatives.
Researching more into this mass extinction I found out that the main theory on this extinction is that a large comet or asteroid has collided into the Earth. By colliding into earth it release a giant dust cloud of debris and a clay called iridium blocked out the sun, thus extremely reducing photosynthesis.
After this research, I came up with a hypothesis. Since the vampire squid lived more then 1,000m deep in the ocean and survived this extinction, I believe that it's relatives lived closer to the surface, within the epipelagic and mesopelagic zones. Since the comet/asteroid's cloud of iridium block the sun it reduced photosynthesis and oxygen levels. Squids need a certain amount of oxygen to survive.
I think that the families were highly adaptive to the high oxygen level that when it started to decrease they were not able to adapt quickly enough to this drastic change. Also, since their prey has decrease drastically, there was not enough food to feed them all.
Since the vampire squid was deep enough it wasn't effected as much as it's relatives. It was already adaptive to low oxygen levels and little prey.
Do you think that this would've been the reason why or do you think different?
"Mass Extinction-New World Encyclopedia." Info:Main Page-New World Encyclopedia. Web. 15 Apr. 2011. http://www.newworldencyclopedia.org/entry/Mass_extinction#Cretaceous-Tertiary_extinction
Campbell, Neil A. Biology. 8th ed. San Francisco: Pearson Education, 2008. 522+. Print
Thanks for researching possible answers to my question. I think your hypothesis makes a lot of sense. Since the soft bodies of squid do not fossilize well, I guess scientists would not know the diet of the extinct families. If they did know what the extinct squids ate, they might be able to know about where it lived depth wise by considering at what depth its prey lived.
ReplyDeleteI agree with you meaghan, I think that due to the low amounts of oxygen and the high demands of squid and octopus the relatives of the vampire squid died off, plus the extinction of many fish didnt help them out either if thats what they preyed on.
ReplyDeleteI wonder if the vampire squid always lived in the deep depths or if after the mass exstiction and possibly close to extinction for itself it moved deeper down to find a better chance for survival. Its always another possibility