Feature Type not available

Tutorial 8.3 Plate Deformation - Rift Basins, involves digitizing polylines to intersect with plate boundaries to outline possible rift basins. The resulting polygon is then created as a new feature with the “Feature Type ‘TopologicalClosedPlateBoundary’.” Unfortunately my Windows version of GPlates 2.4 does not include TopologicalClosedPlateBoundary in the list of available feature types. Is this possibly a bug? Or a newcomer learning opportunity? Nothing in the online User Manual appears to identify this feature type. The tutorials and perhaps the manual appear to date from GPlates 2.2.