What is the difference between mount -t nfs3 and mount -t nfs -o nfsvers=3?

While mounting a share I had issues with idmapping. Mounting with

sudo mount -t nfs 192.168.0.23:/myshare ./myshare -o nolock

and listing its contents yielded this (note the nobody and 4294967294):

-rwx------ 1 nobody 4294967294   48 Sep 27  1998 somefile

When I actually expected this:

-rwx------ 1 1023 1023   48 Sep 27  1998 somefile

I tried using NFSv3 by specifying -t nfs3 without luck:

sudo mount -t nfs3 192.168.0.23:/myshare ./myshare -o nolock,nfsvers=3

After a bit of research, the nfsvers=3 option did the trick

sudo mount -t nfs 192.168.0.23:/myshare ./myshare -o nolock,nfsvers=3
ls -la myshare

...
-rwx------ 1 1023 1023   48 Sep 27  1998 somefile

My question is: what's the difference between the nfsvers=3 option and -t nfs3? Shouldn't they be the same thing?

@håkan-lindqvist is onto the answer. I don't have a mount.nfs3 but I have a mount.nfs4 and it is just a symlink to mount.nfs. I looked at the source for mount.nfs and it doesn't do anything special based on the basename of argv[0] (except for unmounting). Thus mount -t nfs4 would not specify the version at all. I suspect the same for -t nfs3.

So, to answer your questions: they are not the same thing and -t nfs3 doesn't specify the nfs version.