Audiospectrograms and sections of mating calls of Hyla microcephala group:
(a) H. m. microcephala (KU Tape No. 19);
(b) H. robertmertensi (KU Tape No. 41);
(c) H. phlebodes (KU Tape No. 6);
(d) H. sartori (KU Tape No. 190).
Table 4.
—Comparative Cranial Osteology of Hyla microcephala Group
| Character | H. microcephala | H. robertmertensi | H. phlebodes | H. sartori |
| Frontoparietal | Minimally ossified with large fontanelle extending from sphenethmoid to occipital ridge. | Ossification extensive anteriorly with narrow medial separation; fontanelle largest in parietal region. | Ossification extensive anteriorly with narrow medial separation; fontanelle largest in parietal region. | Ossification moderately extensive anteriorly; medial separation of about uniform width throughout length of fontanelle. |
| Nasals | Moderately long and slender; arcuate in dorsal view. | Moderate in size; slightly wider anteriorly than posteriorly in dorsal view. | Moderate in size; slightly wider anteriorly than posteriorly in dorsal view. | Long and broad; arcuate in dorsal view. |
| Sphenethmoid | Extremely short in dorsal view. | Moderately short in dorsal view. | Moderately short in dorsal view. | Moderately short in dorsal view; ossified anteriorly between nasals. |
| Columella | Distal and greatly expanded. | Distal and slightly expanded or not. | Distal and not expanded. | Distal and not expanded. |
Fig. 5.Dorsal views of the skulls of (a) Hyla m. microcephala (KU 68293) and (b) H. sartori(UMMZ S-2677). Both × 12.