taxonID	type	description	language	source
794487B6D6218614F92CFC90FDFBFF73.taxon	discussion	The taxonomy of fossil plants from the Fruitland and Kirtland For ­ mations is confused. Most work has been based on the taxonomy of F. H. Knowlton, a preeminent paleobotanist of the early twentieth century. However. Knowlton, as was customary in his time, placed many Cretaceous specimens in modem taxa on the basis of gross mor ­ phological similarities (e. g .. Ficus, Laurus) and with no regard to variability of the foliage on one plant. Initial collections were made by Bauer and his party (Knowlton, 1916) and later, smaller samples were reported by other USGS geologists (Lee. I 9 I 7; O ’ Sullivan et. al., 1972). Specimens were collected more recently by Kues et al. (1977), Tidwell et al. (1981) and Robison et al. (1982). Large undescribed collections, principally made by J. McClammer, are at NMMNH and YPM. Most recent workers (e. g., Kues et al .. 1977; Tidwell et al .. 1981) considered the Fruitland and Kirtland floras as one entity. We present separate floral lists for both formations (Tables 1, 2) because they represent such different environmental settings and different ages. No megafossil plant specimens have been recovered from the Naashoibito Member of the Kirtland Formation. All early collections of plant fossils from the “ Ojo Alamo Sandstone " of older usage were from the upper conglomerate or Ojo Alamo Sandstone of modem workers and not from the Naashoibito Member of the Kirtland, which earlier workers con ­ sidered to be part of the “ Ojo Alamo. " Additional specimens reported by Lee (1917) are from an undivided Fruitland-Kirtland sequence (“ Laramie ”) near Dulce, but it is clear that they are from the lower Fruitland Formation (Lee, 1917, plate 25 A). It is not clear if other floras reported by Lee (1917), for example from near Durango, are from the Fruitland or Kirtland. O’ Sullivan et al .. (1972) listed specimens from an undivided Fruitland-Kirtland sequence, and these occurrences are not re ­ peated in Table 1. Kues et al. (1977) and Tidwell et al. (1981) both reported new occurrences but did not report, with a few exceptions, which of the two formations their specimens came from. Taxa that could not be assigned to either formation were not included and this, unfortunately, includes most of the palm diversity. There are no recent detailed studies of the floras of the Fruitland and Kirtland Formations. Therefore, interpretations of differences in diversity must be considered preliminary, but we think that such comparisons are of some utility. It is clear that although the floras of the Fruitland and Kirtland Formation are of about equal diversity, there are major differences between the two floras (Tables 1, 2). Ferns are more common in the Kirtland, which reflects the fact that modem fems in the tropics are more common in upland and better drained areas (Berry, 1924). The genus Anema has modern species that are restricted to swamps (Tidwell et al., 1981) and is restricted to the Fruitland. Conifers are more diverse in the Fruitland flora, and taxa that are important in swamp communities, such as Brachyphyllum macrocarpum and Sequoia cuneata (Parker, 1976; Tidwell et al., 1981) are restricted to the Fruitland. The Kirtland flora (Table 2) contains fewer monocots, which are represented by several families not found in the Fruitland (e g., Cyperaceae, Araceae. Cannaceae). Palms arc only present in the Fruitland. The dicots form the majority of plant specimens in both the Fruitland and Kirtland floras (Tidwell et al., 1981). Dicots are more diverse at Scizaeaceae Anemia hesperia Anemia sp. Polypodiaceae? Asplenium coloradense Coniferophyta Araucariaceae Araucaria sp. Araucaria longifolia Cupressaceae Brachyphyllum macrocarpum Taxodiaceae Sequoia reichenbachii Sequoia obovata? Sequoia cuneata Cunninghamites pulchellus Anthophyta Monocotyledonae Palmae Sabalites imperialis Sabalites montana Sabalites sp. Pontederiaceae Heteranthera cretacea Dicotyledonae Saliceae Salix baueri Salix sp. Fagaceae Quercus baueri Moraceae Ficus squarrosa? Ficus rhamnoides Ficus planicostata Ficus praetrinervis Ficus starkvillensis? Ficus praelatifolia Ficus curta? Ficus wardii Ficus baueri Ficus leei Ficus sp. Nymphaeceae Nelumbo sp. Cercidiphylluaceae? Cercidiphyllum sp. Menispermaceae Menispermites sp. Magnoliacea Magnolia cordifolia Lauraceae Laurus baueri Laurus coloradensis Cinnamomum sezannense Saxifragaceae Ribes neomexicana Leguminosae? Leguminosites neomexicana Rhamnaceae Rhamnus goldianus? Zizyphus sp. Myrtacea Myrtophyllum torreyi Incertae sedis Phyllites neomexicanus Phyllites petiolatus Pterospermites undulatus Pterospermites sp. Carpites baueri Carpites sp. Filicophyta Filicophyta Asplenium neomexicana Asplenium sp. Onoclea neomexicana Woodwarthia crenata Salyinaceae Salvinia sp. Coniferophyta Araucariaceae Araucaria sp. Taxodiaceae Sequoia cuneata Anthophyta Monocotyledonae Cyperaceae Cyperacites sp. Araceae Pistia corrugata Cannaceae? Canna maqnifolia Dicotyledonae Salicaceae Salix lancensis Juglandaceae Carya antiquorum Fagaceae Dryophyllum subfalcatum Moraceae Ficus crossii Ficus leei Menispermaceae Menispermites belli Magnoliacea Maqnifolia berryi Lauraceae Laurus coloradensis Laurophyllum salcifolium Laurophyllum wardiana Laurophyllum sp. Platanaceae Platanus nobilis Platanus raynoldsi Leguminosae? Leguminosites neomexicana Rhamnaceae Rhamnus goldianus Rhamnus minutus? Zizyphus sp. Vitaceae Vitis lobata Cissus marginata Dillenaceae Dillenites cleburni Myrtacea Myrtophyllum torreyi Myrtophyllum neomexicanum Caprifoliaceeae Viburnum antiquum Incertae sedis Pterospermites sp. Carpites baueri Carpites lancensis Carpites sp.? Ficus trineruis unidentified flowers and fruit the family level in the Fruitland, being represented by 14 families as opposed to 12 in the Fruitland. However, the specific diversity is apparently greater in the Fruitland flora, particularly within the Moraceae (Table 1). The floral evidence agrees with a general increase in drainage from the Fruitland to Kirtland. The abundance of medium-sized angiospermous leaves with entire or nearly entire margins and drip points suggests a warm-temperature to subtropical climate during deposition of both formations by analogy with modern floras (Lucas, 1981; Tidwell et al., 1981; Robison et al., 1982).	en	Hunt, A. P., Lucas, S. G. (1992): Stratigraphy, paleontology and age of the Fruitland and Kirtland Formations (upper Cretaceous), San Juan Basin, New Mexico. In: Lucas, S. G., Kues, B. S., Williamson, T. E., Hunt, A. P. (Eds): New Mexico Geological Society. New Mexico Geological Society 43 rd Annual Fall Field Conference Guidebook: 217-239, DOI: 10.5281/zenodo.3614972
794487B6D6238614FB3FFAD9F7FCFB46.taxon	discussion	A large number of turtles are present in the Fruitland and Kirtland faunas (Tables 5 - 7). Unfortunately, as is true of most Mesozoic faunas, most turtles are represented solely by shells. There is some debate about the utility of shells in turtle taxonomy (e. g., Gaffney, 1972), and the diversity of turtle taxa listed here is probably inflated.	en	Hunt, A. P., Lucas, S. G. (1992): Stratigraphy, paleontology and age of the Fruitland and Kirtland Formations (upper Cretaceous), San Juan Basin, New Mexico. In: Lucas, S. G., Kues, B. S., Williamson, T. E., Hunt, A. P. (Eds): New Mexico Geological Society. New Mexico Geological Society 43 rd Annual Fall Field Conference Guidebook: 217-239, DOI: 10.5281/zenodo.3614972
794487B6D6238614F97BFE99F7D8F865.taxon	discussion	Introduction The vertebrate faunas of the Fruitland and Kirtland Formations rep ­ resent the largest and most diverse Late Cretaceous faunas of the southern Western Interior and have a long history of collection and study (Hunt et al., 1992). Three vertebrate faunas can be discriminated within the Fruitland and Kirtland Formations; (1) Fruitland Formation (Table 5); (2) Hunter Wash Member, Farmington Member and De-na-zin members of the Kirtland Formation (Table 6); and (3) Naashoibito Member of the Kirtland Formation (Table 7). These faunas form a sequence of decreasing diversity. This is in part due to the fact that the majority of microvertebrate sites are in the Fruitland Formation. Microvertebrate localities account for all the mammalian and amphibian fossils from these strata. It is unfortunate that some recent authors (e. g., Weishampel, 1990) continue to list the fauna of the Kirtland as a whole despite the long realization that two faunas of demonstrably different ages are present in this formation (e. g., Lehman, 1981; Lucas, 1981; Lucas et al .. 1987). Microvertebrates Virtually all fish, amphibian and reptiles, apart from turtles and dinosaurs, are represented by disarticulated microvertebrate specimens. The taxonomy of these specimens is, by necessity, largely typological, but they are comparable with contemporaneous faunas in the Western Interior (e. g., Estes, 1964; Sahni, 1972; Bryant, 1989).	en	Hunt, A. P., Lucas, S. G. (1992): Stratigraphy, paleontology and age of the Fruitland and Kirtland Formations (upper Cretaceous), San Juan Basin, New Mexico. In: Lucas, S. G., Kues, B. S., Williamson, T. E., Hunt, A. P. (Eds): New Mexico Geological Society. New Mexico Geological Society 43 rd Annual Fall Field Conference Guidebook: 217-239, DOI: 10.5281/zenodo.3614972
794487B6D6238613FB3FF93FFE7AFC8B.taxon	discussion	The dinosaur faunas of the Fruitland and Kirtland Formations were first described in detail by Gilmore (1916), who based his study on specimens collected by Bauer and Reeside. Subsequently, the collections of Charles Sternberg were described by Wiman (1930, 1931, 1932, 1933), Osborn (1923), Gilmore (1935) and Ostrom (1960, 1961). Kues et al. (1977), Lehman (1981), Rowe et al. (1981), Lucas et al. (1987) and others have described subsequent discoveries (Tables 5 - 7). Bryozoa? Conopeum sp. Crustacea? Xanthoidea sp. Bivalvia Ostrea glabra Anomia gryphorhynchus A large, undescribed collection from the upper Fruitland has been amassed by Wolberg and co-workers in the Fossil Forest area. These specimens are dominated by disarticulated material but include partial skeletons (Hunt, 1984, 1991). They are housed at the University of Kansas and are being described by J. P. Hall. Anomia gryphaeiformis Modiola latiscostata Unio holmesianus Unio amarillensis Unio gardneri Unio reesiderei The dinosaur specimens from the Fruitland and Kirtland Formations largely consist of disarticulated and isolated bones. Partial skeletons and skulls are uncommon (e. g., Wiman, 1930; Ostrom, 1961). Unio brachypisthus Unio neomexicanus Unio brimhallensis The dinosaur faunas of the Fruitland and Kirtland Formations were recently reviewed by Lucas et al. (1987). However, in the last 5 years there has been a marked increase in the literature on dinosaur taxonomy Unio cf. Unio primaevus Corbicula cytheriformes Corbula chacoensis Panopaea simulatrix Teredina neomexicana Teredina sp. Gastropoda Neritina baueri Neritina sp. Campeloma amarillensis Tulotoma thompsoni Bivalvia Melania insculpta? Unio pyramidatoides? Goniobasis subtortuosa Unio baueri Physa reesidei Unio sp. Physa sp. Gastropoda Planorbis chacoensis Viviparus sp. Chondrichthyes Selachii Hybodontidae Lonchidion selachos? Lonchidion selachos Hybodus sp. Isuridae Isurus sp. Orectolobidae Squatirhina americana Squatirhina sp. Batoidea Dasyatidae Myledaphus bipartitus Myledaphus sp. Pristidae Ischyrhiza avonicola Ptychotrygon cf. P. triangularis Squatirhina sp. Osteichthyes Acipenseriformes Acipenser cruciferus Polyodontidae Paleopsephurus wilsoni Amiiformes Amiidae Amia fragosa Amia cf. Amia uitaensis Amia sp.? Amia chauliodeia Meivius thomasi Lepidosteiformes Lepisosteidae Atractasteus occidentalis Atractasteus sp. Elopiformes Phyllodontidae Paralbula casei Paralbula cf. P. casei cf. Pseudoegertonia sp. Perciformes Sciaenidae Platacodon nanus Amphibia Anura Discoglossidae Scotiophryne pustulosa Pelobatidae? Eopelobates sp. Urodela Prosirenidae Prodesmodon cf. P. copei Batrachosauroididae Opisthotriton kayi? Urodela Cuttysarkus mcnallyi Reptilia Testudines Baenidae " Baena " nodosa Boremys pulchra Compsemys sp. Neurankylus eximius Dermaternydidae Adocus bossi Adocus kirtlandius Adocus sp.? Basilemys sp. Trionychidae Aspideretes sp. Trionyx sp. indet Sauria Teiidae Leptochamops denticulatus Chamops segnis Anguidae cf. Gerrhonotus sp. gen. et sp. indet. Serpentes Aniliidae Coniopholis cosgriffi Crocodilia Crocodylidae Brachychampsa sp.? Brachychampsa sp. Leidyosuchus sp.? Thoracosaurus sp. indet Saurischia Ornithomimidae cf. Ornithomimus sp. indet Dromaeosauridae indet Troodontidae indet Tyrannosauridae? Albertosaurus libratus? Albertosaurus sp. n. gen. et sp. Ornithischia Nodosauridae indet Ankylosauria indet Pachycephalosauridae indet Ceratopsidae Pentaceratops sternbergii indet Hypsilophodontosauridae? Thescelosaurus sp. Hadrosauridae Kritosaurus navajovius Parasaurolophus cyrtocristatus? Corythosaurus sp. Reptilia incertae sedis egg-shell fragments Mammalia Multituberculata Neoplagiaulacidae Mesodma sp.? Mesodma sp.? new genus and species? Neoplagiaulacidae Cimexomys cf. C. judithae Ptilodontidae Mesodma cf. M. senecta cf. Kimbetohia campi? Ptilodontidae Mesodma n. sp. or Cimexomys cf. C. antiquus Cimolodontidae Cimolodon electus Cimolodon n. sp. near C. nitidus Cimolodon sp. cf. Cimolodon sp. Eucosmodontidae new genus and species cf. Eucosmodontidae n. gen. et sp. Cimolomyidae Meniscoessus intermedius cf. Essonodon n. sp.? Essonodon sp. Family incertae sedis Paracimexomys judithae Paracimexomys n. sp.? Essonodon sp. indet Metatheria Didelphidae Alphadon halleyi Alphadon parapraesagus Alphadon cf. A. wilsoni Alphadon cf A. marshi Alphadon n. sp. A Alphadon n. sp. B cf. Peradectes sp. Ectocentrocristus foxi Pediomyidae Pediomys fassetti Pediomys cf. P. cooki Aquiladelphis paraminor Stagodontidae cf. Eodelphis sp. Eutheria Leptictidae? Gypsonictops clemensi Gypsonictops cf. G. lewisi Gypsonictops n. sp. Palaeoryctidea Cimolestes lucasi cf. Cimolestes sp.? Nyctitheriidae Paranyctoides cf. P. sternbergii Eutheria incertae sedis indet TABLE 7. Vertebrate fauna of the Naashoibito Member of the Kirtland For ­ mation from Brown (1910), Hay (1908, 1910), Gilmore (1916, 1919. 1922). Wiman (1931, 1933), Mateer (1976), Kues et al. (1977), Lehman (1981, 1984, 1985), Lucas et al. (1987) and this paper. Chondrichthyes Osteichthyes Selachii Lepisosteidae Atractasteus sp. Cyprinidae indet Reptilia Testudines Baenidae " Baena " nodosa Thescelius insiliens Neurankylus eximius Compsemys sp. Trionychidae Aspideretes vorax Aspideretes fontanus Aspideretes austerus Dermatemydidae Adocus vigoratus Basilemys nobilis Holplochelys cf. H. bicarinata Crocodilia Goniopholididae Goniopholis sp. Crocodylidae indet Saurischia Ornithomimidae indet Dromaeosauridae indet Tyrannosauridae? Albertosaurus sp. cf. Tyrannosaurus sp. Saurornithoididae indet Sauropodomorpha Titanosauridae Alamosaurus sanjuanensis Ornithischia Ankylosauridae indet Nodosauridae? Panoplosaurus sp. indet Ankylosauria indet Ceratopsidae Torosaurus cf. Torosaurus latus indet Hadrosauridae Edmontosaurus saskatchewanensis Parasaurolophus tubicen indet Mammalia Multituberculata Neoplagiaulacidae Mesodma formosa Cimolomyidae Essonodon browni cf. Meniscoessus sp. Metatheria Didelphidae Alphadon marshi Alphadon sp. Squatirhinidae indet Batoidea Dasyatidae Myledaphus sp. Osteichthyes Amiiformes Amiidae? Amia chauliodeia Melvius thomasi Lepidosteiformes Lepisosteidae Atractasteus occidentalis Atractasteus sp. Reptilia Testudines Baenidae " Baena " nodosa " Baena " ornata " Baena " sp. Boremys pulchra Neurankylus eximius Thescelus insiliens Dermatemydidae Adocus bossi Adocus kirtlandius Basilemys nobilis Trionychidae Aspideretes ovatus Aspideretes vorax Plastomenus robustus Plastomenus sp. Platypeltis sternbergi Crocodilia Goniopholidae Goniopholis kirtlandicus Crocodylidae Brachychampsa sp. Leidyosuchus sp.? Thoracosaurus sp. Saurischia Ornithomimidae cf. Struthiomimus sp. Dromaeosauridae indet Tyrannosauridae Albertosaurus sp. Aublysodon cf. A. mirandus Ornithischia Nodosauridae? Euplocephalus sp. indet Ankylosauria indet Ceratopsidae cf. Chasmosaurus sp. Pentaceratops fenestratus Hadrosauridae Kritosaurus navajovius Parasaurolophus sp. Mammalia Multituberculata Neoplagiaulacidae Mesodma formosa Cimolomyidae cf. Meniscoessus sp. Metatheria Didelphidae Alphadon marshi with the publication of two important books (Weishampel et al .. 1990; Carpenter and Currie. 1990). Thus, we briefly review some aspects of the faunas and describe some recently collected specimens. Unfortunately, the recent literature lacks species-level revisions of some of the most important taxa, notably the Hadrosauridae, Ceratopsidae and Tyrannosauridae.	en	Hunt, A. P., Lucas, S. G. (1992): Stratigraphy, paleontology and age of the Fruitland and Kirtland Formations (upper Cretaceous), San Juan Basin, New Mexico. In: Lucas, S. G., Kues, B. S., Williamson, T. E., Hunt, A. P. (Eds): New Mexico Geological Society. New Mexico Geological Society 43 rd Annual Fall Field Conference Guidebook: 217-239, DOI: 10.5281/zenodo.3614972
794487B6D6248613FF45FAF1FF02FA79.taxon	discussion	Several localities in the Fruitland and Kirtland yield nodosaurid scutes. Keeled scutes of nodosaurids can be distinguished from ankylosaurids in that ankylosaurid scutes are commonly excavated on their medial surface and thus are thin (Coombs and Maryanska, 1990). In contrast, nodosaurid scutes tend to be flat or only slightly cupped on their medial surface (Coombs and Maryanska, 1990). NMMNH P- 20880 (Fig. 8 K-L) represents the first specimens of a nodosaurid reported from the Fruitland Formation. These specimens are thick, keeled plates with only slightly concave medial surfaces. NMMNH P- 1078 (Fig. 8 I-J) is two large keeled plates of a nodosaur from the Naashoibito Member of the Kirtland Formation. These plates are similar to dorsal scutes of Edmontia (Coombs and Maryanska. 1990, fig. 22.13 upper).	en	Hunt, A. P., Lucas, S. G. (1992): Stratigraphy, paleontology and age of the Fruitland and Kirtland Formations (upper Cretaceous), San Juan Basin, New Mexico. In: Lucas, S. G., Kues, B. S., Williamson, T. E., Hunt, A. P. (Eds): New Mexico Geological Society. New Mexico Geological Society 43 rd Annual Fall Field Conference Guidebook: 217-239, DOI: 10.5281/zenodo.3614972
794487B6D6248613FF46FE07FD9DF94A.taxon	discussion	— Carnosaur specimens are rare in the Fruitland and Kirtland Formations. Although generically indeterminate, one specimen worthy of note is NMMNH P- 20879 (Fig. 8 M), a pedal phalanx from the Kirtland Member. NMMNH P- 20879 is comparable with phalanges of Tarbosaurus (Molnar et al., 1990, fig. 6.12 E) and undoubtedly represents the third phalanx of the fourth digit of the right pes. The record of tyrannosaurids in the San Juan Basin is poor, with only one partial skeleton (of Aublysodon) known from either the Fruit ­ land or Kirtland Formations (Lehman and Carpenter, 1990). It is not even clear if this taxon is a tyrannosaur (Molnar et al., 1990). The only questionable record of Tyrannosaurus is based on an isolated tooth from the Naashoibito Member of the Kinland Formation (Lucas et al., 1987). Tyrannosaurid taxonomy is in a state of flux, as is obvious if the recent classifications of Paul (1988), Molnar et al. (1990) and Carpenter (1990) are compared. Until the family is revised and the osteology of some important taxa (e. g .. Tyrannosaurus) are described, it is difficult to identify fragmentary specimens.	en	Hunt, A. P., Lucas, S. G. (1992): Stratigraphy, paleontology and age of the Fruitland and Kirtland Formations (upper Cretaceous), San Juan Basin, New Mexico. In: Lucas, S. G., Kues, B. S., Williamson, T. E., Hunt, A. P. (Eds): New Mexico Geological Society. New Mexico Geological Society 43 rd Annual Fall Field Conference Guidebook: 217-239, DOI: 10.5281/zenodo.3614972
794487B6D624860EFF47F8D2FC82F9CC.taxon	discussion	Several partial skeletons of hadrosaurs have recently been recovered from the Fruitland and Kirtland Formations. One such specimen from the Naashoibito Member was recently described by Hunt and Lucas (1991). A second partial skeleton is of an indeterminate hadrosaur from the upper Fruitland Formation of Ah-shi-sle-pah Wash (Fig. 8 A-C, F-H). This specimen is interesting in that two '? successive ribs show healed fractures at about their midpoint (Fig. 8 B-C). A third hadrosaur skeleton from the Naashoibito Member of the Kirtland Formation includes much of a skull (Fig. 9) and associated postcranial elements (Fig. 8 D-E). This specimen represents a hadrosaurine, as it possesses an anterodorsal process on the maxilla (Homer, 1990) and has a flat dorsal skull profile (skull roof not illustrated). The most diagnostic element is the jugal (Fig. 9 A-D). The rounded lower margin of the lateral temporal fenestra, the narrow elongate postorbital process and the nearly right angle formed by the ventral margin below the lateral temporal fenestrae are of taxonomic value. In all these char ­ acters, NMMNH P- 1041 differs from Judithian and Edmontonian taxa and from the Lancian hadrosaurines Anatotitan (Weishampel and Horner, 1990, fig. 26.5 C), Edmontosaurus regalis (Lull and Wright, 1942, fig. 52) and E. annectens (Lull and Wright, 1942, fig. 53). However, the new specimen closely resembles the jugal of Edmontosaurus saskatchewanensis (Lull and Wright, 1942, fig. 56; Weishampel and Horner, 1990, fig. 26.5 a) and we tentatively assign NMMNH P- 1041 to this taxon. Fruitland and Kirtland hadrosaurs have been most recently placed in three species, Kritosaurus navajovius, Parasaurolophus tubicen and P. cyrtocristatus (Lucas et al., 1987). Recently it has been suggested that Kritosaurus is either a junior subjective synonym of Hadrosaurus or Gryposaurus (e. g., Chapman and Brett-Surman. 1990) or that the genoholotype of Kritosaurus is indeterminate (Weishampel and Horner, 1990). The genoholotype of Kritosaurus (AMNH 5799) is a poorly preserved skull that is truncated at the anterior margin of the orbits. The entire lower jaw is preserved. We believe that this specimen can be distinguished from all other hadrosaur taxa and forms a basis for a distinct genus. Thus, Kritosaurus can be distinguished from most other hadrosaurine hadrosaurs (e. g., Edmontosaurus, Anattitan, Maiasaura, Prosaurolophus, Saurolophus, Shantungosaurus) by the high, short lateral profile of the skull. Kritosaurus is distinguished from Brachylophosaurus by the lack of a posterior extension of the nasals dorsal to the orbit, from Aralosaurus by the possession of much larger lateral temporal fenestrae and from Hadrosaurus by differences in the ilium (see below). We consider Kritosaurus to be a valid genus and a sub ­ jective senior synonym of Gryposaurus, contra Weishampel and Homer (1990). Hadrosaurus foulkii is based on a partial postcranial skeleton and fragments of a skull (Lull and Wright, 1942, figs. 45 - 50). Only the postcranial specimens are complete enough for comparison with ma ­ terial of Kritosaurus (Lull and Wright, 1942; Pinna, 1979). The ilium is the most distinct of the elements represented in the skeleton of Hadrosaurus. Comparison of the ilia of Hadrosaurus foulkii (Leidy, 1856; Lull and Wright, 1942) and Kritosaurus navajovius (Parks, 1920) indicates that there are significant differences between the two taxa (Fig. 10). The ilium of Hadrosaurus is distinguished principally by having a deeper and more abruptly tapering anterior process (Fig. 10). Davies (1983) noted the following other differences between the ilia of Hadrosaurus and Kritosaurus: (1) the antitrochanter is weak with little or no ventral deflection in Hadrosaurus, whereas in Kritosaurus the antitrochanter is robust with a strong ventral deflection; (2) the ridge extending anteriorly on the dorsal margin is weak with a short, straight extension onto the posterior process in Hadrosaurus, but in Kritosaurus the ridge is well developed and extends anteriorly on the dorsal margin; (3) in Hadrosaurus, posterior end of the antitrochanter is midway down onto the body of the ilium with a faint ridge extending dorsocaudally onto the posterior process; and (4) the ratio of acetabular length / height is less in Hadrosaurus (0.82) than Kritosaurus (0.92). These differences are consistent with the variation between genera rather than within genera (cf. Brett-Surman, 1975). We conclude that Kritosaurus is not a junior subjective synonym of Hadrosaurus. We consider that there are no significant differences between Kri ­ tosaurus navajovius and Kritosaurus notabilis and that they are synonyms. Kritosaurus breviceps (based on a partial dentary) and Kritosaurus marginatus (based on fragmentary postcrania) were assigned to the genus by Lull and Wright (1942) but we consider them nomina dubia. Kritosaurus incurvimanus is based on the posterior part of a skull and lower jaws and exhibits no differences from K. navajovius. Thus, we consider Kritosaurus to be a monospecific genus consisting only of K. navajovius. Brown (in Sinclair and Granger, 1914) identified a maxilla and in ­ complete dentary (AMNH 5797) from the Naashoibito Member of the Kirtland Formation as belonging to Kritosaurus. However, these elements are not diagnostic at the generic level. Lucas et al. (1987) iden ­ tified a right lower jaw of a hadrosaur from the Naashoibito Member as Kritosaurus (Lucas et al., 1987). This specimen is also generically indeterminate. Thus, there is no evidence for the presence of the had ­ rosaurine Kritosaurus in the Naashoibito Member of the Kirtland Formation. Two of the three species of Parasaurolophus, P. tubicen and P. cyrtocristatus, have been named for specimens from the Fruitland and Kirtland Formations. It is significant that the only three good skulls of Parasaurolophus were all named as different species (cf. Lucas, 1991). However, pending a revision of this genus, we consider both the San Juan Basin species to be valid. Hopson (1975) and Weishampel (1981) considered that the long crested P. walkeri and P. tubicen represent males and the short crested P. cyrtocristatus a female. Given that Parasaurolophus is rare in all faunas in which it occurs, is only known from three good skulls from three different stratigraphic units and that none of the three species co-occur, we consider speculations about sexual dimorphism in this genus to be unwarranted.	en	Hunt, A. P., Lucas, S. G. (1992): Stratigraphy, paleontology and age of the Fruitland and Kirtland Formations (upper Cretaceous), San Juan Basin, New Mexico. In: Lucas, S. G., Kues, B. S., Williamson, T. E., Hunt, A. P. (Eds): New Mexico Geological Society. New Mexico Geological Society 43 rd Annual Fall Field Conference Guidebook: 217-239, DOI: 10.5281/zenodo.3614972
794487B6D6248613FF46FBC7FCB5F81A.taxon	discussion	— The only described sauropod from the Fruitland or Kirtland is Alamosaurus sanjuanensis (Gilmore, 1922). Wolberg et al. (1988) listed a “ new genus and species of titanosaurid " from the Fruit ­ land Formation. However, lacking any documentation of this occur ­ rence, we do not include it in our faunal lists.	en	Hunt, A. P., Lucas, S. G. (1992): Stratigraphy, paleontology and age of the Fruitland and Kirtland Formations (upper Cretaceous), San Juan Basin, New Mexico. In: Lucas, S. G., Kues, B. S., Williamson, T. E., Hunt, A. P. (Eds): New Mexico Geological Society. New Mexico Geological Society 43 rd Annual Fall Field Conference Guidebook: 217-239, DOI: 10.5281/zenodo.3614972
794487B6D639860EFF90FB47F717FC52.taxon	discussion	Four taxa of ceratopsians are currently recognized from the Fruitland and Kirtland Formations. Cf. Chasmosaurus is based on a horn core that can be reasonably assigned to this taxon (Gilmore, 1935; Lucas et al., 1987). Pentaceratops is represented by two putative species. Having examined all the skulls of these species, we conclude that only P. sternbergii is valid. Pentaceratops fenestratus is based on a skull distinguished only by an accessory " foramen " on one side of the frill (Wiman, 1930). Since this " foramen " is only present on one side of one frill (Mateer, 1981, pl. 3.1), it is probably a pathology. The skeleton described by Wiman (1930) as Pentaceratops was found with ­ out a skull and its affinities are presently unknown. Dodson and Currie (1990) suggested that Pentaceratops might be a subjective junior synonym of Chasmosaurus. These genera are similar, but we believe that relative elongation of the frill in Pentaceratops is a diagnostic difference. However, we urge further study of the various skulls of Pentaceratops to gauge variation in this genus. The presence of Pentaceratops in the Naashoibito Member of the Kirtland Formation is based on three specimens (Lucas et al., 1987). Lucas et al. (1987, fig. 5 F) illustrated an indeterminate partial frill and postcranial elements. This specimen represents a small ceratopsian with well-developed epoccipitals that is distinct from Torosaurus, the other Naashoibito ceratopsian. Similarly, USNM 12741 is an indeterminate partial skull of a small ceratopsian. OSM 40 - IX- 1 - 41 through 40 - IX- 44 - 41 is a skull and postcranial skeleton of Pentaceratops sternbergii. However, this specimen is not from the Naashoibito Member as stated by Lucas et al. (1987). This specimen was found " in highly carbo ­ naceous flaky shale containing plant fragments & much fossil resin " (Langston in Kues et al., 1977, p. 377). Since no megafossil plant remains have ever been found in the Naashoibito Member, it is certain that the Oklahoma specimen came from lower in the Fruitland-Kirtland sequence. The presence of abundant plant debris, fissile carbonaceous shale and amber strongly suggests that this specimen derives from the Fruitland Formation. In summary, no diagnostic specimens of Penta ­ ceratops have been recovered from the Naashoibito Member of the Kirtland Formation and it is likely that the small identified ceratopsian represents the same taxon as is found in other Lancian localities in the southern Western Interior (Lehman, 1987). Torosaurus specimens from the Naashoibito were previously assigned to the species T. utahensis, but this is now considered a junior subjective synonym of T. latus (Dodson and Currie, 1990). We strongly doubt that T. latus is a male Triceratops, as suggested by Ostrom and Wellnofer (1990). Triceratops is unknown in the southern Rocky Mountains where Torosaurus occurs, although these taxa co-occur in the northern Western Interior. More strikingly, the number of known individuals of Triceratops compared to the number of individuals of Torosaurus is more than 50: 1. Given this ratio and their geographic disparity it is unlikely that these taxa are sexual dimorphs, ignoring morphological details.	en	Hunt, A. P., Lucas, S. G. (1992): Stratigraphy, paleontology and age of the Fruitland and Kirtland Formations (upper Cretaceous), San Juan Basin, New Mexico. In: Lucas, S. G., Kues, B. S., Williamson, T. E., Hunt, A. P. (Eds): New Mexico Geological Society. New Mexico Geological Society 43 rd Annual Fall Field Conference Guidebook: 217-239, DOI: 10.5281/zenodo.3614972
794487B6D639860EFB3AFE2BF98CFE95.taxon	discussion	Mammalian fossils were first recovered from the Fruitland Formation by W. A. Clemens in the 1960 s (Clemens, 1973). From the mid- 1970 s to the mid- 1980 s large-scale screenwashing was carried out by E. H. Lindsay (University of Arizona), D. L. Wolberg (New Mexico Bureau of Mines and Mineral Resources) and J. K. Rigby Jr. (formerly of the U. S. Bureau of Land Management and now at Notre Dame University). The majority of these collections have not been described, notably the University of Kansas specimens collected by Clemens and the nontherians from the Fossil Forest area under study by Wolberg and Rigby. Flynn (1986) described the more limited collections from the University of Arizona, and Rigby and Wolberg (1987) studied the therian mammals from the Fossil Forest area.	en	Hunt, A. P., Lucas, S. G. (1992): Stratigraphy, paleontology and age of the Fruitland and Kirtland Formations (upper Cretaceous), San Juan Basin, New Mexico. In: Lucas, S. G., Kues, B. S., Williamson, T. E., Hunt, A. P. (Eds): New Mexico Geological Society. New Mexico Geological Society 43 rd Annual Fall Field Conference Guidebook: 217-239, DOI: 10.5281/zenodo.3614972
