page_title: Timeline of tyrannosaur research
section_title: 1990s
hierarchical_section_title: Timeline of tyrannosaur research / 20th century / 1990s
caption_attribution_description: Tyrannosauripus pillmorei, probable Tyrannosaurus footprint from w:Philmont Scout Ranch, New Mexico
context_page_description: This timeline of tyrannosaur research is a chronological listing of events in the history of paleontology focused on the tyrannosaurs, a group of predatory theropod dinosaurs that began as small, long-armed bird-like creatures with elaborate cranial ornamentation but achieved apex predator status during the Late Cretaceous as their arms shrank and body size expanded. Although formally trained scientists did not begin to study tyrannosaur fossils until the mid-19th century, these remains may have been discovered by Native Americans and interpreted through a mythological lens. The Montana Crow tradition about thunder birds with two claws on their feet may have been inspired by isolated tyrannosaurid forelimbs found locally. Other legends possibly inspired by tyrannosaur remains include Cheyenne stories about a mythical creature called the Ahke, and Delaware stories about smoking the bones of ancient monsters to have wishes granted.
  Tyrannosaur remains were among the first dinosaur fossils collected in the United States. The first of these was named Deinodon horridus by Joseph Leidy. However, as this species was based only on teeth the name would fall into disuse.
context_section_description: 1990
  José Bonaparte and others classified tyrannosaurs as carnosaurs.
  Molnar classified tyrannosaurs as carnosaurs.
  Sue, catalog name FMNH PR 2081, the largest and most complete T.rex skeleton yet found, discovered on August 12, 1990 on the Cheyenne River Indian Reservation in South Dakota.
  1991
  Farlow and others studied tyrannosaur tooth biomechanics, finding them to be more resistant to forces in both the front-to-back and side-to-side planes than the more blade-like teeth of other carnivorous dinosaurs.
  Scotty the T.Rex is discovered near Eastend, Saskatchewan.
  1992
  Kenneth Carpenter described the new genus Maleevosaurus.
  William Abler studied tyrannosaur tooth biomechanics. He concluded that the serrations on tyrannosaur teeth did not function like the serrations on a saw blade. Instead he thought the serrations may have caught pieces of rotting meat inside them, sustaining bacterial colonies that make its bite likely to transmit deadly infections to potential prey items. Similar use of decaying meat trapped in tooth serrations as a vector for infected prey had been reported in monitor lizards.
  Fernando Emilio Novas performed a phylogenetic analysis of the tyrannosauridae, finding tyrannosaurs to actually be coelurosaurs, as advocated by a few contrarian workers during the 1920s, rather than carnosaurs as had been generally supposed for decades. Novas found them equally related to the ornithomimosaurs and maniraptorans.
  1993
  Bernardino Pérez Pérez-Moreno and others performed another phylogenetic analysis of the Tyrannosauridae and found additional support for reclassifying the family as coelurosaurs. They found that within the coelurosaurs, tyrannosaurs were arctometatarsalians. In other words, they were more closely related to the ostrich dinosaurs than to birds.
  Farlow found that the ancient ecology of tyrannosaur habitats were inconsistent with the idea that they were scavengers.
  Horner and Donald Lessem interpreted tyrannosaurids as scavengers.
  1994
  Pérez-Moreno and others performed another phylogenetic analysis of the Tyrannosauridae and found additional support for reclassifying the family as coelurosaurs. They found tyrannosaurids to lie outside of the maniraptoriformes. In other words, they are less closely related to birds than the ostrich dinosaurs are.
  Thomas Holtz performed another phylogenetic analysis of the Tyrannosauridae and found additional support for reclassifying the family as coelurosaurs. He found that within the coelurosaurs, tyrannosaurs were arctometatarsalians. In other words, they were more closely related to the ostrich dinosaurs than to birds.
  Horner interpreted tyrannosaurids as scavengers.
  Martin Lockley and Hunt described a possible Tyrannosaurus footprint.
  1995
  Emily B. Giffin observed that the brachial plexus of the tyrannosaurid neural canal was smaller than those of other theropods, suggesting that tyrannosaurids really did have reduced forlimb function.
  Farlow and others calculated that an adult T. rex running at 20 m/s or faster would sustain fatal injuries if it tripped, suggesting that they didn't actually run that fast.
  Holtz observed that tyrannosaurids had the longest limbs relative to their body size of any theropod dinosaurs apart from the ostrich dinosaurs and a small, slender ceratosaur called Elaphrosaurus. Although the ostrich dinosaur on average had relatively longer limbs overall, the ratios of femur length to the length of the tibia and fibula were actually very close between the smaller tyrannosaurs and the largest ostrich dinosaurs. Holtz found ostrich dinosaurs and tyrannosaurs to have other traits of the hindlimb in common as well. Both groups had a pinched third metatarsal, called an arctometatarsus, that strengthened the foot. Holtz concluded that these traits indicated that tyrannosaurids were among the best adapted for running of all carnivorous dinosaurs.
  1996
  Osmólska described the new genus and species Bagaraatan ostromi.
  Gregory Erickson and Kenneth Olson reported the existence of ornithischian bones with T. rex bite marks.
  Erickson and Olson others cal
caption: Lockley and Hunt reported a possible T. rex footprint in 1994.
exif: {"Image ImageDescription": "MINOLTA DIGITAL CAMERA", "Image Make": "Minolta Co., Ltd.", "Image Model": "DiMAGE Z1", "Image Orientation": "Horizontal (normal)", "Image XResolution": "72", "Image YResolution": "72", "Image ResolutionUnit": "Pixels/Inch", "Image Software": "Adobe Photoshop CS3 Windows", "Image DateTime": "2010:10:08 14:20:11", "Image YCbCrPositioning": "Co-sited", "Image PrintIM": "[80, 114, 105, 110, 116, 73, 77, 0, 48, 50, 53, 48, 0, 0, 4, 0, 1, 0, 22, 0, 22, 0, 2, 0, 0, 0, 0, 1, 0, 1, 0, 0, 0, 1, 1, 1, 0, 0, 0, 0]", "Image ExifOffset": "324", "Thumbnail Compression": "JPEG (old-style)", "Thumbnail XResolution": "72", "Thumbnail YResolution": "72", "Thumbnail ResolutionUnit": "Pixels/Inch", "Thumbnail JPEGInterchangeFormat": "1126", "Thumbnail JPEGInterchangeFormatLength": "7345", "EXIF ExposureTime": "1/125", "EXIF FNumber": "5", "EXIF ExposureProgram": "Program Normal", "EXIF ISOSpeedRatings": "50", "EXIF ExifVersion": "0220", "EXIF DateTimeOriginal": "2006:08:05 16:20:28", "EXIF DateTimeDigitized": "2006:08:05 16:20:28", "EXIF ComponentsConfiguration": "YCbCr", "EXIF CompressedBitsPerPixel": "2", "EXIF BrightnessValue": "34/5", "EXIF ExposureBiasValue": "0", "EXIF MaxApertureValue": "3", "EXIF MeteringMode": "Pattern", "EXIF LightSource": "Unknown", "EXIF Flash": "Flash did not fire, compulsory flash mode", "EXIF FocalLength": "29/5", "EXIF SubjectArea": "[1024, 768, 44, 29]", "EXIF FlashPixVersion": "0100", "EXIF ColorSpace": "sRGB", "EXIF ExifImageWidth": "1797", "EXIF ExifImageLength": "1482", "Interoperability InteroperabilityIndex": "R98", "Interoperability InteroperabilityVersion": "[48, 49, 48, 48]", "EXIF InteroperabilityOffset": "1000", "EXIF FileSource": "Digital Camera", "EXIF SceneType": "Directly Photographed", "EXIF CustomRendered": "Custom", "EXIF ExposureMode": "Auto Exposure", "EXIF WhiteBalance": "Auto", "EXIF DigitalZoomRatio": "0", "EXIF FocalLengthIn35mmFilm": "38", "EXIF SceneCaptureType": "Standard", "EXIF GainControl": "None", "EXIF Contrast": "Normal", "EXIF Saturation": "Normal", "EXIF Sharpness": "Normal", "EXIF SubjectDistanceRange": "2"}