When The Terrordactyls appear on Vashon this Sunday afternoon, it will be both a homecoming and a send-off for band members Michael Cadiz and Tyrel Stendahl.

The show, slated for 4 p.m. Sunday, Sept. 28, at Vashon Island Music Studio, will mark the launch of the band’s second national tour, with stops planned in 45 cities in 28 states.

With rising reputations on the indie-rock scene, thousands of Myspace friends and impressive connections to better-known musicians, Cadiz, 24, and Stendahl, 23, seem well on their way to achieving national recognition. They have three CDs under their belt, with a fourth in progress. Their animated video for “Devices,” a duet between Cadiz and free folk chanteuse Kimya Dawson, has gotten international airplay.

But it wasn’t long ago that the duo got its start on Vashon, during a particularly fertile and supportive time for Island youth.

Cadiz and Stendahl, both Islanders, met in 1998 in a freshman Vashon High School multimedia class, and immediately teamed up to make what Stendahl now calls “dorky little animations and videos.”

That summer, they began making music together.

“It seemed like that was just what kids on Vashon did,” Stendahl said. “Being from a small Island, we could be creative and no one would tell us otherwise.”

Stendahl credits the Vashon Youth Council, a non-profit organization for young people aged 13 to 20, as being one of the cornerstones of support for the then-vibrant youth music scene on Vashon.

The council’s youth-run club, The Crux, opened in 1999 and was first housed in the building behind the Department of Licensing office on Bank Road. It later moved to the storefront now occupied by Treasure Island.

“The Crux was a place to play other than our garages,” Stendahl said. “We were just playing for our friends, and no one was super good, but it was original, and being creative comes before being good. I think a lot of people have that backwards.”

Jean Navarre, an Islander who volunteered at the Crux and donated money to provide the space with recording equipment, called the group of young people who played at The Crux “my ‘hokey-pokeys’ — because they are what life’s all about.”

The Crux was shuttered, due to lack of funding, in 2004, but the legacy of the space continues.

Other Crux alumni include members of the band The Pharmacy, another Vashon band that has acheived national recognition and is now on its first European tour. The Pharmacy band member Brendan Bowers was also one of the founding members of The Terrordactyls.

Stendahl and Cadiz both graduated from Evergreen State College last May, and despite several moves that took them off the Island, they have kept in touch with the Vashon Crux crowd.

“Everyone is still playing music,” said Stendahl. “It’s pretty mind-boggling.”

The Terrordactyls bring a wide and quirky array of instrumentation to their performances, including guitar, piano, toy piano, xylophone and a kazoo “horn section.”

Tickets for the band’s show at Vashon Island Music are $5 each, and are on sale now at the store. Seating is limited and pre-purchase of tickets is recommended. The first 30 people will receive a free kazoo with their ticket purchase. The show is appropriate for all ages.

To sample the band’s music and check out merchandise designed by Stendahl, visit www.myspace.com/theterrordactyls.