20th century
... that during the 20th century, the first large-scale excavation of dinosaur footprints was undertaken in Texas for an exhibit at the American Museum of Natural History?
... that during the <b id="mwB_A"><a href="./20th_century_in_ichnology" id="mwB_E" rel="mw:WikiLink" title="20th century in ichnology">20th century</a></b>, the first large-scale excavation of <a class="mw-redirect" href="./Dinosaur_footprints" id="mwB_I" rel="mw:WikiLink" title="Dinosaur footprints">dinosaur footprints</a> was undertaken <a href="./Paleontology_in_Texas" id="mwB_M" rel="mw:WikiLink" title="Paleontology in Texas">in Texas</a> for an exhibit at the <a href="./American_Museum_of_Natural_History" id="mwB_Q" rel="mw:WikiLink" title="American Museum of Natural History">American Museum of Natural History</a>?