Sylvia Romano is the daughter of Giorgio and Maria Romano and the first human that Arthur and Will Denison meet on Dinotopia. She worked with her parents at the Hatchery, but met the Denisons again in Treetown, a reunion which Arthur suspected that she and Will had planned. She and Will later won the youth games at Treetown, and Brokehorn offered them the first choice of which habitat they would like to train for. Both answered "the sky" and were thus sent to Canyon City to train as Skybax Riders. Sylvia was paired with a Skybax named Nimbus.
After Arthur departed into the World Beneath, Sylvia accompanied Will on his pilgrimage to the Tentpole of the Sky, a refuge high in the central mountains of Dinotopia. The pair were well received by the monks there, and reaffirmed their dedication to be Skybax riders. Sylvia and Will then departed on a dirigible, but it was wrecked in a storm. Seeking refuge in Sauropolis, Will and Sylvia were surprised to find Cirrus and Nimbus waiting for them, as Oolu had known all along they would pass their test. The pair were also surprised to learn that Arthur and Bix had left the capital only days before, their own journey having brought them home. While resting in Sauropolis, Will realized that he was in love with Sylvia, but realizing that Arthur, Giorgio and Maria would all think them too young, decided to put off proposing marriage. Will and Sylvia returned to Waterfall City for an emotional reunion with Arthur.
Sylvia and Will were still flying missions together in 1867, when they were assigned to be decoys for caravans passing the Rainy Basin, based out of the border village of Bonabba. While there, the pair learned that Brokehorn's infant grand hatchling, Strongbrow ("Stubbs") was ill. Sylvia joined a twilit procession in the town's Garden of Hope in support of Stubbs, and later agreed to keep an eye out for the rare plants needed to make his medicine. After the Denison Expedition unexpectedly turned up in the Rainy Basin, Sylvia flew point when they went after the rogue Lee Crabb. During the race to the sea that concluded the expedition, Sylvia flew to Prosperine to secure the assistance of a pair of northies, who in turn managed to rescue Arthur and Crabb from a watery grave.
Non Canon apearences
In the miniseries, Sylvia of the Hatchery was assigned as Zippo's human partner. By 2002, she had died, and Zippo still missed her.  In the miniseries continuity, she seems to have not been a Skybax rider.