Martin Lockley

Martin Lockley
University of Colorado | UCD · Department of Geography and Environmental Sciences

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Introduction
Skills and Expertise

Publications

Publications (484)
Chapter
The three field guides in this volume, associated with GSA Connects 2022 held in Denver, Colorado, USA, tackle some interesting aspects of Colorado geology and paleontology. Learn about dinosaur tracks, microbial mat, and applied photogrammetry at Dinosaur Ridge; explore the nature and extent of the Mesoproterozoic Picuris orogeny in Colorado; and...
Article
An increasing number of theropod-dominated tracksites have been reported from the Jurassic and Cretaceous of China. These include a significant number from the Lower Jurassic of the Lufeng Basin, famous for its Lufengosaurus fauna and known for a typical Lower Jurassic globally-distributed tetrapod footprint biochron. Here we report another localiz...
Article
An isolated but moderately well-preserved theropod track from the coal-bearing strata of the Zhangjiakou City region of Hebei Province was reported to have originated from the Xiahuayuan Formation, which is considered Middle Jurassic in age. Although the track has a wide divarication angle and length-width ratio reminiscent of Cretaceous tracks lik...
Article
The Late Jurassic, ‘single surface’ Moab Megatracksite between Green River, Utah and the Colorado-Utah State line is associated with the sharp, colour-enhanced, inter-formational contact between white, reworked dune sandstones from the aeolian Moab Member of the Curtis Formation and red, sabkha facies siltstones and sandstones of the upper tongue o...
Article
The transition between the aeolian Moab Member of the Curtis Formation and the marginal marine upper tongue of the Summerville Formation, in the area of Arches National Park, Utah, facilitated the registration of the distinctive theropod-dominated Moab Megatracksite complex, which is something of an ichnological cause célèbre. The complex reveals t...
Article
A newly discovered saurischian dominated tracksite in the Lower Cretaceous Jiaguan Formation in southeastern Sichuan province reveals 13 sauropod trackway segments representing ichnogenus Brontopodus and three theropod trackways. This is a typical Type 1 Jiaguan Formation deposit dominated by tetrapod tracks with no significant tetrapod body fossil...
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We report the first occurrence of the track type “Chirotherium” lulli from western North America. Three specimens were discovered at the “Feather Ridge Tracksite” in the Owl Rock Member of the Chinle Formation within Bears Ears National Monument of San Juan County, Utah. The ichnospecies occurs in association with Grallator isp., Brachychirotherium...
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The Mail Station Dinosaur Tracksite (MSDT), situated on Bureau of Land Management land in San Juan County, Utah, is one of the largest and best-preserved Lower Jurassic dinosaur tracksites in the western USA. The site is located stratigraphically near the top of the Navajo Sandstone Formation (Glen Canyon Group) and is dominated by large theropod t...
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As part of a 1930s public works project, two specimens revealing a total of ~20 tracks, preserved as natural casts, were collected and built into the interior walls of what was then the Fruita Museum in western Colorado. Based on our knowledge of the regional tetrapod ichnofaunas we are able to designate these as a "Triassic specimen" and a "Jurass...
Chapter
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The Cretaceous ankylosaurian ichnogenus Tetrapodosaurus is only found abundantly in two regions, in North America: in the Aptian-Albian Gething and Gates Formations of western Canada and the Albian-Cenomanian Dakota and Naturita Formations of Colorado. While tracks from both regions have been reported in a number of papers, the Colorado discoveries...
Article
Abstract—The distinctive sauropodomorph ichnogenus Eosauropus has been recognized as the first tetrapod ichnogenus reported from the Late Triassic Chinle Group strata of the Purgatoire Valley in southeastern Colorado. The trackway, from the Alejandro Canyon area, is represented by17 consecutive pes footprints, and 6 recognizable manus tracks regist...
Article
Subaqueously-registered trackways of marine tetrapods are only rarely preserved; some of the best examples so far come from the Shizishan Member (Member II) of the Guanling Formation (Middle Triassic, Anisian-Ladinian) of Yunnan Province in southwestern China. The unit is well-known for the Luoping Biota including abundant skeletons of marine repti...
Article
Abundant well-preserved bird tracks from lacustrine Green River Formation (Eocene) deposits in Utah, are diverse and paleoecologically significant, but remain poorly known. Three of the four previously reported morphotypes (A-D) are named here for the first time with two representing new ichnotaxa. In order of increased footprint length (L) the ich...
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A new Middle Jurassic tracksite dominated by non-avian theropod footprints from the Wangjiashan Formation in Pingchuan District, Baojishan Basin, Gansu Province has yielded a unique trackway with four consecutive manus-pes sets. Only three previous examples, all Early Jurassic in age, of theropod trackways are known with convincing examples of manu...
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Small theropod tracks, ichnogenus Minisauripus, from the Jinju Formation (Cretaceous) of Korea reveal exquisitely preserved skin texture impressions. This is the first report for any dinosaur of skin traces that cover entire footprints, and every footprint in a trackway. Special sedimentological conditions allowed footprint registration without sme...
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A relatively small number of tetrapod tracksites from Zhejiang Province fills out the fossil record from that region, which is also known to have yielded both saurischian (titanosauriform, coelurosaur) and ornithischian (basal ornithopod, ankylosaurian) body fossils as well as dinosaurian eggs. We use photogrammetry and 3D imaging to reinterpret th...
Article
Newly discovered frog tracks from the Lower Cretaceous (upper Aptian–lower Albian) Jinju Formation, South Korea, represent only the second report from Asia, and only the third global report from the Mesozoic. They are also the oldest reported from the fossil record, and can be assigned to Ranipes isp. indet. These tracks add to the rapidly growing...
Article
The rapid rate of discovery of Lower Cretaceous tetrapod tracksites in terrestrial sequences on the Sichuan Basin area is such that the 2016 report of 21 sites in the Xiaoba, Feitianshan and Jiaguan Formations is now increased by ∼24%–26 sites. Of these seven occur in the Xiaoba Formation, including two new sites (Luogan and Apuruha) described here...
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East of Still Bay on the Cape south coast of South Africa lies a rugged, remote stretch of sea cliffs that expose Late Pleistocene aeolianites. A zone of dense concentration of fossil tracks occurs within this area. Two large rocks, which we call Roberts Rock and Megafauna Rock, were identified ~400 metres apart. These rocks contained a variety of...
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Ongoing studies of a multiple track-bearing horizons from massive excavations in the Jinju Formation (Lower Cretaceous) of South Korea have yielded a remarkable diversity of avian, nonavian dinosaur, pterosaur, crocodilian and mammal tracks, many very small and well preserved. Here we report diminutive, didactyl tracks (~1.0 cm long) assigned to a...
Article
A newly discovered Jiaguan Formation (Lower Cretaceous) tracksite from the Linjiang region of Guizhou Province, China, reveals the first example of a Cretaceous track morphotype attributable to the non-avian theropod ichnogenus Gigandipus, here named G igandipus chiappei ichnosp nov. The theropod dominated locality also reveals the second report of...
Article
The vertebrate track Laiyangpus liui, from the Lower Cretaceous of Shandong Province in China has been the subject of misunderstanding and misinterpretation since it was discovered and named in 1960, and reposited in the Institute of Vertebrate Paleontology and Paleoanthropology collections in Beijing. It was initially misinterpreted as evidence of...
Article
The Grand Valley of western Colorado, centered on Grand Junction, is world famous for many dinosaur discoveries dating from the early 20 th Century. However, these discoveries largely revolve around skeletal remains of Jurassic dinosaurs and other tetrapods. Here we report on the discovery of Cretaceous tracks from several sites representing the Da...
Article
The only described Cretaceous frog tracksite known from North America, from outcrops of the Blackhawk Formation in Meetinghouse Canyon, Utah, had previously, additionally yielded only a small number relatively large, unnamed tetradactyl avian theropod (bird) tracks. Unnamed avian dinosaur (bird) and non-avian dinosaur tracks had also been reported...
Article
A large assemblage of more than 100 archosaur tracks was recovered from the Cretaceous “Dakota Formation” (Naturita Formation) at a high elevation site on private land in the Cedar Canyon area of southwestern Utah. The assemblage is notable for several reasons. It consists exclusively of large, deep, and well preserved natural casts. All three majo...
Article
The newly discovered large (350 m²) Yantan dinosaur tracksite, in the Lower Jurassic Ziliujing Formation of Guizhou Province, China, reveals at least 250 footprints of which ∼97 can be resolved into trackways of sauropodomorphs. All the trackways are sub parallel likely indicating gregarious behavior. One theropod track (cf. Grallator) was recorded...
Article
At least 16 tetrapod tracksites have been reported from the Cretaceous Jingchuan Formation of the Ordos Basin, in the Chabu area, of Otog Qi, Inner Mongolia. Only a few of these sites, designated as Chabu sites 1–16, have been documented in detail. Most known sites occur in an area of ∼100 km² and are saurischian dominated, yielding the tracks of s...
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Type specimens of the sauropod ichnotaxon Chuxiongpus changlingensis, which was later reassigned to Brontopodus changlingensis, as well as the theropod ichnotaxon Yunnanpus huangcaoensis, both from the Cretaceous Jiangdihe Formation of Yunnan Province, are redescribed in order to document their morphological features. Both, but particularly Y. huan...
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Although only recognized as a discrete stratigraphic unit since 1944, the Cedar Mountain Formation represents tens of millions of years of geological and biological history on the central Colorado Plateau. This field guide represents an attempt to pull together the results of recent research on the lithostratigraphy, chronostratigraphy, sequence st...
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Tetrapod ichnofaunas are reported from desert, playa lake facies in the Lower Cretaceous Luohe Formation at Baodaoshili, Shaanxi Province, China, which represent the first Asian example of an ichnnofauna typical of the Chelichnus Ichnofacies (Brasilichnium sub-ichnofacies) characteristic of desert habitats. The mammaliomorph tracks, assigned to Bra...
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Many newly-discovered dinosaur tracksites have recently been reported from the Lower Cretaceous Dasheng Group of Shandong Province. These are proving valuable as tools for characterizing the fauna in deposits almost devoid of body fossils. Here we report on a new Cretaceous site, the 14th documented in recent years, with multiple track-bearing leve...
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A Late Pleistocene hominin tracksite has been identified in coastal aeolianite rocks on the Cape south coast of South Africa, an area of great significance for the emergence of modern humans. The tracks are in the form of natural casts and occur on the ceiling and side walls of a ten-metre long cave. Preservation of tracks is of variable quality. U...
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Newly discovered frog tracks from the Cretaceous of Saok Island, South Korea, represent the first report of anuran (frog) tracks from the Phanerozoic of Asia and, only the second global report of Mesozoic anuran tracks. This is also the first global report of frog track assemblages with multiple trackways from multiple stratigraphic levels. The tra...
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A newly discovered assemblage of predominantly small tracks from the Cretaceous Patuxent Formation at NASA's Goddard Space Flight Center, Maryland, reveals one of the highest track densities and diversities ever reported (~70 tracks, representing at least eight morphotypes from an area of only ~2 m2). The assemblage is dominated by small mammal tra...
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A newly discovered Upper Cretaceous (Maastrichtian) dinosaur tracksite in the Laramie Formation near Marshall, Boulder County, Colorado, here called the Cherryvale site, has yielded several dozen dinosaur tracks of theropods and ornithopods. Among the most abundant and distinctive are the slender-toed theropod tracks Saurexallopus isp. indet., whic...
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Two tridactyl footprints from the Chuangjie Formation (Middle Jurassic) of Yunnan Province, China are morphological characteristics of thyreophoran tracks. They show some similarities to Shenmuichnus, known from the Early Jurassic strata of both Shaanxi and Yunnan provinces, but are somewhat larger, thereby resembling the ichnogenus Stegopodus. Bas...
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The fossil record of horseshoe crabs (Xiphosurida) from the Mesozoic of North America consists of only three name-bearing specimens from the Cretaceous. We add to this depauperate record the first report of a horseshoe crab body fossil from the Triassic of North America. It comes from a locality in the Olenekian (Spathian) Thaynes Group, near Paris...
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Late Triassic and Early Jurassic tetrapod track assemblages are abundant and quite well documented from the respective Chinle and Glen Canyon groups of the Dolores Valley region of western Colorado and adjacent regions, especially eastern Utah. However, gaps still exist in our knowledge of the spatial and temporal distribution of representative ich...
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The Ignotornidae had a global distribution during the Cretaceous (Aptian – Cenomanian), but reports have been limited to North America, and localities in South Korea. Until recently, despite the high diversity of Ignotornidae described from Asia, no ichnospecies of Ignotornidae have been described from China. Here we report the first occurrence of...
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In July 2017, a team from China University of Geosciences (Beijing) found some invertebrate traces and vertebrate tracks on a hill (GPS: 31°13'53.35"N, 95° 57'18.95"E, altitude 3739 m) east of Jue’en Township, Dingqing County, Changdu City, Tibet Autonomous Region. According to the 1:250000 scale geologic mapping of Dingqingfu area (No. H46C001004)...
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The use of drones in the exploration and documentation of track surfaces in steep terrain, otherwise only accessible by time intensive climbing activity, is tested. Location is the Nanquan site, one of many now known footprint localities from the Lower Cretaceous Dasheng Group that has been recently exposed by local industrial excavation. It reveal...
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Tetrapod footprints from the coal-bearing, Upper Cretaceous beds of Colorado, Wyoming and Utah, loosely known as the “Mesaverde” Group, have been reported and collected, mostly for Utah and Colorado institutions since the 1920s. However, it has only been in recent decades that the track assemblages have been reexamined in any detail. The results of...
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Upper Triassic and Middle Jurassic strata of the Xichang Basin in Sichuan Province, southwestern China, yielded important dinosaur ichnofossils. From the Xujiahe Formation of the Yiguojiao tracksite, we report a Late Triassic footprint assemblage in China and the first discovery of diagnostic Triassic sauropodomorph tracks in this region. The track...
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The Cretaceous bird trackway originally labeled Aquatilavipes anhuiensis, in 1994, had previously been examined, photographed and replicated, but never described or illustrated in detail. However, it has been part of a widening discussion about the distribution of Aquatilavipes and Koreanaornis in China (and Korea). Here we illustrate and formally...
Data
Abstract GIUSEPPE LEONARDI and PAOLO MIETTO (Eds) THE ITALIAN DINOSAURS Note that many chapters of this book are here in my page of ResearchGate with full text, abstract and images. Search for chapters of year 2000. A VERY EXPANDED ABSTRACT IN ENGLISH (THE ORIGINAL TEXT IS IN ITALIAN WITH THIS EXPANDED ABSTRACT AT THE END OF THE BOOK) ----- THE JUR...
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Previously-unknown large scale scrapes attributed to Cretaceous theropod dinosaurs from the Naturita Formation (formerly the Dakota Sandstone) of western Colorado were recently named as Ostendichnus bilobatus and interpreted as evidence of “nest scrape display,” a type of courtship behavior previously known only in extant avians. However, comparati...
Article
The Qingquan dinosaur tracksite, from the Lower Cretaceous Dasheng Group, Shandong Province, China adds to the growing record of saurischian-dominated ichnofaunas of the region. The site reveals the presence of avian theropods (Koreanaornis) and non-avian theropods tentatively referred to Jialingpus. Sauropod tracks are referred to Brontopodus. One...
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Two relatively small tridactyl tracks from the Middle Jurassic Xintiangou Formation of northeastern Sichuan are assigned to cf. Anomoepus based on low length/width and anterior triangle ratios, and a relatively short step and inward rotation of the footprint axes. Anomoepus is typical of many Middle Jurassic dinosaur-dominated ichnofaunas from cent...
Article
Despite the extreme, well-documented abundance of tracks of herbivorous dinosaurs (ornithopods and sauropods), avian theropods and pterosaurs, from the Cretaceous of Korea the footprints of non-avian theropods have previously been reported only sporadically from the Cretaceous Gyeongsang Supergroup of Korea, without clear attribution to any ichnoge...
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We describe late Miocene tetrapod footprints (tracks) from the Trachilos locality in western Crete (Greece), which show hominin-like characteristics. They occur in an emergent horizon within an otherwise marginal marine succession of Messinian age (latest Miocene), dated to approximately 5.7 Ma (million years), just prior to the Messinian Salinity...
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Didactyl tracks of theropod affinity are reported in this study based on a small sample of footprints in sandstones within the Middle Jurassic (Aalenian-Bajocian) Dansirit Formation in the Baladeh area, Alborz Mountains, Iran. These tracks superficially resemble footprints attributed to small deinonychosaurian dinosaurs known mainly from the Cretac...
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A previously unknown and morphologically distinct pentadactyl mammal track was recovered from the Upper Cretaceous (Maastrichtian) Laramie Formation at the Fossil Trace site, a National Natural Landmark which it's the type locality for Schadipes crypticus, the only named mammal track known from North America. The track is different, and larger than...
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Sauropod tracks from the Early Jurassic Maanshan Member of the Ziliujing Formation in the Dazhuanwan area of Guizhou represent the first Jurassic dinosaur track record for this province. The best preserved and longest trackway is narrow gauge (Brontopodus type), and indicates a relatively small trackmaker (footprint length ~35.0 cm). In conjunction...
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Two new dinosaur tracksites are reported from the Lower Cretaceous Jiaguan Formation in the Sichuan Basin, Qijiang District of Chongqing. These are the Gaoqing-Yongsheng and the Huibu tracksites, which represent the 13th and 14th reports from this formation. The Gaoqing-Yongsheng tracksite reveals the trackway of a large biped (ornithopod) in assoc...