FIGURE 2. A in Oology And The Evolution Of Thermophysiology In Saurischian Dinosaurs: Homeotherm And Endotherm Deinonychosaurians?

FIGURE 2. A. Incubating troodontid in a desert/semi-desert environment in Asia (rendered by artist Doyle Trankina). Note the position of the incubating parent on the egg clutch as its axial skeleton rests on the vertically/sub-vertically orientated eggs, a position that contrasts with that of oviraptorids where mostly their appendicular skeleton covers the clutch. Furthermore, there is no space without eggs in the clutch center as observed in oviraptorids and unidentified Chinese Macroolithid egg clutches. B. Partial troodontid egg clutch from China (LX09XLOZLX0001-2156). Although not associated with any skeletal remains, taxonomic identification was supported by the eggshell microstructure and egg morphology.Note that the asymmetric shape of these eggs due to the presence of a well developed air cell (arrows) and that the pointed pole faces down with the eggs buried nearly up to the level of the location of the air cell (doted lines). C. SEM of eggshell spared from the region indicated by the white rectangle. Note the presence of two prismatic layers, here separated by a dotted lines, with layer 1 consisting of blade-shaped calcite crystals.