The website you directed to states:
"Usually there are still gaps between each of the groups -- few or none of the speciation events are preserved."
Thre are changes within species, microevolution, as any dog or horse breeder can tell you, but we still seem to be missing credible transitional form info except for those who choose to believe in evolution.
You are correct. Here is a nice transitional (I hope posting data in the Religion Forum is OK). Note its position in the chart which follows (hint--in the upper center):
Site: Koobi Fora (Upper KBS tuff, area 104), Lake Turkana, Kenya (4, 1)
Discovered By: B. Ngeneo, 1975 (1)
Estimated Age of Fossil: 1.75 mya * determined by Stratigraphic, faunal, paleomagnetic & radiometric data (1, 4)
Species Name: Homo ergaster (1, 7, 8), Homo erectus (3, 4, 7), Homo erectus ergaster (25)
Gender: Female (species presumed to be sexually dimorphic) (1, 8)
Cranial Capacity: 850 cc (1, 3, 4)
Information: Tools found in same layer (8, 9). Found with KNM-ER 406 A. boisei (effectively eliminating single species hypothesis) (1)
Interpretation: Adult (based on cranial sutures, molar eruption and dental wear) (1)
See original source for notes:
Source: http://www.mos.org/evolution/fossils/fossilview.php?fid=33
Source: http://wwwrses.anu.edu.au/environment/eePages/eeDating/HumanEvol_info.html