What were the largest animals to survive the KT extinction?

[aplomado]

What were the largest animals to survive the KT extinction?

[Troodon]

10 minutes ago, aplomado said:

What were the largest animals to survive the KT extinction?

I think you have to include crocodilians and sharks in that list

[DPS Ammonite]

Single mushroom/fungus colonies can cover several sqare miles. Per Wikipedia, a colony in Oregon covers 3.4 square miles.

 

Edit: I see that you asked for animals. Fungi are related to but are not animals. 

[siteseer]

On 4/1/2019 at 9:42 AM, Troodon said:

I think you have to include crocodilians and sharks in that list

 

Hi Troodon,

 

Yes, early in the Paleocene the largest sharks would have been Palaeocarcharodon and Sphenodus.  From what I've seen they had the largest teeth so I assume they were at least among the largest sharks.  It's hard to give a size range for an extinct genus with no modern relatives and with only teeth to go by but those two genera were probably in the 10-12 foot range at least in total body length.  Oddly, Sphenodus survived the mass extinction but it disappears from the fossil record by the middle of the Paleocene.  A possible rival would have been the hexanchid, Notodanodon.  I've seen some Cretalamna teeth from that time that were rather large for the genus.  I haven't seen any bony fish remains of anything that would have been at least five feet long.

 

Yes, there were some large crocodilians during that time in freshwater and marine environments.  There were also more terrestrial crocs though those don't appear to have been very common.

 

Early in the Paleocene mammals were no larger than maybe beaver-size.  I've seen only tiny teeth of primates and multituberculates (and other extinct groups) that would have been from individuals smaller than that.  Within 5-8 million years there were bear-sized carnivorous mammals and cow-sized herbivorous forms.

 

Jess

[Troodon]

2 hours ago, siteseer said:

 

Hi Troodon,

 

Yes, early in the Paleocene the largest sharks would have been Palaeocarcharodon and Sphenodus.  From what I've seen they had the largest teeth so I assume they were at least among the largest sharks.  It's hard to give a size range for an extinct genus with no modern relatives and with only teeth to go by but those two genera were probably in the 10-12 foot range at least in total body length.  Oddly, Sphenodus survived the mass extinction but it disappears from the fossil record by the middle of the Paleocene.  A possible rival would have been the hexanchid, Notodanodon.  I've seen some Cretalamna teeth from that time that were rather large for the genus.  I haven't seen any bony fish remains of anything that would have been at least five feet long.

 

Yes, there were some large crocodilians during that time in freshwater and marine environments.  There were also more terrestrial crocs though those don't appear to have been very common.

 

Jess

Dont forget the Otodus lineage.  Pretty barren place in the early days..

[Al Dente]

How about giant squid? There was Tusoteuthis in the Cretaceous and several type today. No idea if they were around immediately after the Cretaceous.

[Troodon]

1 hour ago, Al Dente said:

How about giant squid? There was Tusoteuthis in the Cretaceous and several type today. No idea if they were around immediately after the Cretaceous.

Yes they became the dominant cephalopod and came through.  Not sure sure what species and size survived.

[siteseer]

On 4/4/2019 at 4:02 PM, Troodon said:

Dont forget the Otodus lineage.  Pretty barren place in the early days..

 

I'm not sure Otodus was present in the Early Paleocene though I think I have a tooth that looks like a Cretalamna but seems to lean more toward Otodus.  I'll try to dig it out and get a couple of shots of it.  It might have been present in the Early Paleocene of Russia.

 

Jess

[Natalie81]

On 1-4-2019 at 6:42 PM, Troodon said:

I think you have to include crocodilians and sharks in that list

And turtles 

[siteseer]

7 hours ago, Natalie81 said:

And turtles 

 

Yes, sea turtles survived but I don't know how big they were in the Early Paleocene.  A researcher from that Hornerstown project might have an idea.  It's possible one of the largest animals was a sea turtle.

[Scylla]

Pretty large Paleocene turtles have been found, here is a partial list:

https://en.m.wikipedia.org/wiki/Category:Paleocene_turtles

[MikaelS]

The oldest Otodus I have seen thus far are of NP3 age (O. obliquus group). I suspect Notidanodon was the largest elasmobranch crossing the boundary. Mid-Danian otodontids include several taxa that were probably in the 4-5m range but our knowledge about well dated material of larger sharks from the NP1-2 interval is very poor. Maastricthian otodontids in mid-palaeolatitudes were much smaller than mid-Danian ones.

[Mark Kmiecik]

Unfortunately, the best we can do is speculate, since the fossil record is vastly incomplete, and there were probably many species that lived and survived whose remains were never fossilized for various reasons, one being the environmental niche they occupied. For instance if the species lived at depths of 1,000 feet and never came shallower, how would we know.

[siteseer]

On 4/29/2019 at 5:15 PM, Mark Kmiecik said:

Unfortunately, the best we can do is speculate, since the fossil record is vastly incomplete, and there were probably many species that lived and survived whose remains were never fossilized for various reasons, one being the environmental niche they occupied. For instance if the species lived at depths of 1,000 feet and never came shallower, how would we know.

 

 

Fossils found at Fakse, Denmark come from an Early Paleocene deepwater environment perhaps as deep as 1000 feet.

 

It's true the fossil record is quite incomplete especially for the Early Paleocene but we have a few windows to life on land and at sea even for that time.

[Mark Kmiecik]

10 hours ago, siteseer said:

 

 

Fossils found at Fakse, Denmark come from an Early Paleocene deepwater environment perhaps as deep as 1000 feet.

 

It's true the fossil record is quite incomplete especially for the Early Paleocene but we have a few windows to life on land and at sea even for that time.

Man is only aware of about 15% of extant species. What percent of extinct species would you guess we have discovered? I would guess it's less than 5%.

[Scylla]

3 hours ago, Mark Kmiecik said:

Man is only aware of about 15% of extant species. What percent of extinct species would you guess we have discovered? I would guess it's less than 5%.

Less than 1%. Much less.