This is a transitional, what some journalists or laymen might call a missing link.
Scientists already know about it, along with a number of other intermediate species (see the chart).
Many non-scientists deny this type of evidence for religious reasons, but that does not make it go away, nor does it lessen its significance.
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
What are all of those dotted lines for?
Eventually various other missing pieces may be found to help fill the gaps. At least those gaps in our evolution are smaller and easier to explain than the big gap between Adam and the present (I've long wondered who Cain and Abel married if Adam and Eve were the first two people).