Cretaceous ice ages
As it turns out, the early Cretaceous was not only temperate as Liaoning indicated, but was really, really cold:
There is indirect evidence that a glaciation event existed during the late Aptian-early Cenomanian [approximately 100 MA]. Here in eastern Nebraska the event is recorded by a large-scale, unconformity-bounded sequence of the lower Woodbury Member of the Dakota Sandstone [aka "Muddy-Mowry Seaway" or "Muddy sandstone"]. An eustatic sea-level mechanism lowered worldwide sea-levels by more than 25 m and that this sea-level fall occurred in a rather short period of geologic time. A glacioeustatic component is most likely to account for the observed sea-level changes during the mid-Cretaceous “greenhouse” world. I'm not aware of the existence of large-scale continental ice sheets. But, a Southern Hemisphere polar ice sheet with limited extent and volume compared to “icehouse” continental ice sheets, and global alpine glaciers that were fed by wet climate cycles [a local condition which is well documented during Dakota sedimentation] could account for sea-level fluctuations that resulted in valley incision and subsequent filling.
Alley, N.F., and Frakes, L.A. 2003. First known Cretaceous Glaciation: Livingston Tillite Member of the Cadna-owie Formation, South Australia. Australian Journal of Earth Science. v. 50, p. 139-144.
Bornemann, Norris, Friedrich, Beckmann, Schouten, Sinninghe Damsté, Vogel, Hofmann and Wagner.2008. "Isotopic Evidence for Glaciation During the Cretaceous Supergreenhouse" Science Vol. 319 no. 5860 pp. 189-192
Gale, A.S., Hardenbol, J., Hathaway, B., Kennedy, W.J., Young, J.R., and Phansalker, V. 2002. Global correlation of Cenomanian (Upper Cretaceous)sequences: Evidence for Milankovitch control on sea level. Geology. v. 30, p. 291-294.
Haq, B.U., Hardenbol, J., and Vail, P.R. 1987. Chronology of Fluctuating Sea Levels since the Triassic. Science. V. 235, n. 4793, p. 1156-1167.
Immenhauser, A. 2005. High-rate sea-level change during the Mesozoic: New approaches to an old problem. Sedimentary Geology, Vol. 175, p. 277-296.
Ludvigson, G.A., Gonzalez, L.A., Metzger, R.A., Witzke, B.J., Brenner, R.L., Murillo, A.P., White, T.S. 1998. Meteoric sphaerosiderite lines and their use for paleohydrology and paleoclimatology. Geology, v. 26, n. 11, p. 1039-1042.
Miller, K.G., Sugarman, P.J., Browning, J.B., Kominz, M.A., Hernandez, J.C., Olsson, R.K., Wright, J.D., Feigenson, M.D., and Van Sickel, W. 2003. Late Cretaceous chronology of large, rapid sea-level changes: Glacioeustasy during the greenhouse world. Geology. v. 31, no. 7 (July), p. 585-588.
Sahagian, D., Pinous, O., Olferiev, A., and Zakharov, V. 1996. Eustatic Curve for the Middle Jurassic-Cretaceous Based on Russian Platform and Siberian Stratigraphy: Zonal Resolution. AAPG Bulletin. v. 80, no. 9. p. 1433-1458
Stoll, H.M., and Schrag, D.P. 1996. Evidence for glacial control of rapid sea-level changes in the Early Cretaceous. Science. v. 272, p. 1771-1774.