I doubt it. What version of Solaris are you using?
On Solaris 8, I ran 'man -k mount_' and got this:
mount_cachefs mount_cachefs (1m) - mount CacheFS file systems
mount_hsfs mount_hsfs (1m) - mount hsfs file systems
mount_nfs mount_nfs (1m) - mount remote NFS resources
mount_pcfs mount_pcfs (1m) - mount pcfs file systems
mount_s5fs mount_s5fs (1m) - mount s5 file systems
mount_tmpfs mount_tmpfs (1m) - mount tmpfs file systems
mount_udfs mount_udfs (1m) - mount a udfs file system
mount_ufs mount_ufs (1m) - mount ufs file systems
mount_xmemfs mount_xmemfs (1m) - mount xmemfs file systems
I don't think that you would be able to mount any filesystems other than these without first installing the appropriate drivers.