Wrote about this last in 2007.  In THIS Texas Lege session, Charles Geren has introduced a bill to replace the WRONG dinosaur with the RIGHT one. Here's the resolution.  HCR 16

WHEREAS, Texas has become world famous for its many dinosaur  discoveries; and
          WHEREAS, To honor the prehistoric reptiles that long ago  resided in the state, Senate Concurrent Resolution No. 57 of the  75th Texas Legislature named Brachiosaur Sauropod, Pleurocoelus,  as the official Lone Star State Dinosaur; this designation was  based on evidence that supported the presence of the dinosaur  Pleurocoelus in Texas; and
          WHEREAS, Subsequently, the fossilized bones that were  thought to be Pleurocoelus have been properly identified as a new  species named Paluxysaurus jonesi; the identification was made by  Peter Rose during his graduate studies at Southern Methodist  University, and his findings have been widely accepted by other  scientists since being published in 2007; and
          WHEREAS, The dinosaur is named for the town of Paluxy in Hood  County and for the Paluxy River, both of which are near the Jones  Ranch site where the fossils of this species were discovered; and
          WHEREAS, Paluxysaurus jonesi inhabited the earth  approximately 95 to 112 million years ago, and these sauropods left  behind a rich record of their existence; in addition to the bone  fossils, evidence of the species exists in dinosaur footprints that  have been found throughout the state; the most famous of these  trackways runs along the Paluxy River and its tributaries, not far  from the Jones Ranch site; many of these footprints can be viewed at  Dinosaur Valley State Park, near the town of Glen Rose; and
          WHEREAS, The bones and tracks reveal the massive scale of  Paluxysaurus; it is estimated that the dinosaur measured 70 feet  long and 12 feet high at the shoulder, and weighed as much as 20  tons; and
          WHEREAS, Paluxysaurus continues to be the subject of  important paleontological research; a major dinosaur project is  ongoing at the Jones Ranch site, with the work being led by the Fort  Worth Museum of Science and History in partnership with Southern  Methodist University; moreover, a public exhibit of the bones of  Paluxysaurus jonesi is planned for the museum; and
          WHEREAS, Through the insightful work of Texas-based  scientists, the tracks and bones of the large quadrupedal sauropod  found in the Lone Star State are now clearly known to be those of the 
   species Paluxysaurus jonesi rather than Pleurocoelus; and
          WHEREAS, Given the importance of the paleontological  discoveries that have taken place in Texas, it is indeed  appropriate that the designation of our state dinosaur keep pace  with the latest scientific research; now, therefore, be it
          RESOLVED, That the 81st Legislature of the State of Texas  hereby designate Paluxysaurus jonesi as the official Lone Star  State Dinosaur, replacing Brachiosaur Sauropod, Pleurocoelus.

Here's a link to the paper from Rose   I was amused by the title about this on the FW Star-Telegram Politex blog.