Terrestrial vs Fossorial

[lackdawa]

I'm very confused as to what the difference is between the two. Tom Moran explained as, terrestrials live on the surface whereas fossorials live underground, what I don't really get is I feel like so many terrestrials are burrowers but are still classified as terrestrials, not fossorials. Some websites have said a T is terrestrial while others say it's a fossorial, so what exactly is the difference?

 

[Sterls]

Another term we use is obligate versus opportunistic borrowers. Obligates required lots of sub, opportunistics will often take advantage of it if given the chance. Many terrestrials can be opportunistic. They may burrow, they may hang out up top.

 

[The Grym Reaper]

Terrestrial - Opportunistic burrower - Generally lives on the surface, might construct a shallow burrow if it feels like it.
Fossorial - Obligate burrower - Generally lives in a deep burrow, might hang out on the surface if it feels like it.

 

[viper69]

For husbandry

Terr- can thrive without burrowing generally

Fossorial- will not thrive without burrowing generally

 

[Smotzer]

Everything has already been said, but remember tarantulas are individuals and sometimes exhibit slightly different behaviors than the 'norm'.

 

[Ic4ru577]

For fossorial, they will only show you part of its body. Terrestrial will roam the enclosure.

 

[Jesse607]

Also, to clarify, these terms are are used in the tarantula hobby to describe the species general behavior in captivity, not necessarily in the wild. Most or many "terrestrial" species are fossorial in the wild but in captivity they seem to not display burrowing behavior as strongly, especially more mature specimens.

 

[Matt Man]

Terrestrial - digging "eh maybe"
Fossorial - "me like dig"
My C marshalli dug a 1.5" diameter hole about 4" deep in an evening