Agathoxylon Lemonii Sp. Nov., from the Dakota Formation, Utah

Great Basin Naturalist

Volume 46 Number 3 Article 26

7-31-1986

Agathoxylon lemonii sp. nov., from the Dakota Formation, Utah

William D. Tidwell Brigham Young University

Gregory F. Thayn Bureau of Land Management, Salt Lake City, Utah

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Recommended Citation Tidwell, William D. and Thayn, Gregory F. (1986) "Agathoxylon lemonii sp. nov., from the Dakota Formation, Utah," Great Basin Naturalist: Vol. 46 : No. 3 , Article 26. Available at: https://scholarsarchive.byu.edu/gbn/vol46/iss3/26

This Article is brought to you for free and open access by the Western North American Naturalist Publications at BYU ScholarsArchive. It has been accepted for inclusion in Great Basin Naturalist by an authorized editor of BYU ScholarsArchive. For more information, please contact [email protected], [email protected]. AGATHOXYLON LEMONII SP. NOV., FROM THE DAKOTA FORMATION, UTAH

William D. Tidwell' and Gregory F. Thayn"

Abstract. —Petrified wood specimens fi-om the Dakota Formation of Utah are here described as Agathoxylon lemonii . This new species is characterized by having distinct growth rings, araucarian tracheary pitting, resin plates or plugs in its tracheids, abundant axial parenchyma, low uniseriate rays and 1-4 small, slightly bordered pits with circular to oval included apertures per crossfield. This is the first report of petrified wood from the Dakota Formation of the western United States and the first record of Agathoxylon from North America.

Although fossil plant remains are abundant United States. Stanton (1905) in working with in the Dakota Formation, reports of petrified Jurassic and Cretaceous formations and the plant material from this formation are rare. Dakota in southern Colorado, New Mexico, The study of fossil plants in the Dakota For- and Oklahoma, demonstrated that the Dakota mation began in the midwestern United Formation of this region, as originally de- States. Initial collections of fossil plants from fined, contains both Lower and Upper Creta- this formation were obtained during western ceous strata. In Utah the Dakota Formation territorial surveys for a proposed route for a occurs between the Lower Cretaceous Cedar transcontinental railroad in the 1850s and Mountain Formation and the Upper Creta-

1860s (Dilcher et al. 1978). Hayden, in 1853, ceous Mancos Shale and is considered to be was the first to obtain leaves from the Dakota mid-Cretaceous in age. Fossil plants in the Group of Nebraska. He and Meek in 1856-57 Dakota Formation of western Colorado and collected additional plant materials from eastern Utah were first reported by Brown these sediments that were subsequently sent (1950) and later by Tidwell et al. (1967), Rush- to Professor Oswald Heer in Switzerland for forth and Tidwell (1968), and Rushforth (1970, study. Heer (1859) published descriptions of 1971). these materials. This publication represents Brown (1950) described a flora from the the first authentic record of North American Burro Canyon Formation that is more or less Cretaceous plant fossils. equivalent to at least a portion of the Cedar Well-preserved leaves were later collected Mountain Formation (Young 1960, Tschudy in large numbers in Kansas during the 1860s et al. 1984) and a flora from the Dakota Forma- and 1880s by various workers. These collec- tion near Naturita, Colorado. This flora, like tions formed the basis for the first major publi- the Dakota flora from Westwater, Utah, is cations on this flora Lesquereux (1874, bv atypical in that the percentage of ferns is high 1883, 1892). as compared with the number of angiosperms. Subsequent to Lesquereu.x's publica- The Dakota flora near Westwater is domi- tions, very little work had been done on the nated by the ferns Astralopteris Tidwell, lora of the Dakota Formation until recently, Rushforth, and Reveal, Matonidium Schenk, vvhen considerable research on the reproduc- Gleichenia Smith, Hausmania Dunker, As- :ive structures and leaves of early an- plenium L., Cladophlebis Brong., and Conio- ^iosperms from this formation in Kansas was pteris Brong. (Rushforth 1970, 1971). No published (Dilcher et al. 1976, Dilcher et al. coniferous foliage has been reported from this 1978, Dilcher 1979, Retallack and Dilcher flora in Utah. However, Retallack and Dilcher L981). (1981) noted that SequoiaAike foliage, cones, The Dakota Formation extends throughout and cone scales were common conifer nuch of the southwestern and midwestern megafossil material in the Dakota Formation

Department of Botany and Range Science, Brigham Young Uni' iity, Provo. Utah 84602. -Bureau of Land Management, Salt Lake City, Utah 8410L

559 Vol. 46, No. 3 Great Basin Naturalist 560

ray cell (495X) (Holotype). cell contents in upper right side July 1986 TiDWELL, Thayn: Fossil Plant 561

Systematics

Coniferales Agathoxylon Hartig

Agathoxylon lemonii sp. nov.

Figs, 1-9

DiAGNOSLS. —Growth rings distinct, 2-6 mm wide; transition from early to late wood gradual; tracheids generally hexagonal in transverse section, some compressed and oval in outline, approximately 50 (xm in diameter, some slightly elongated radially, walls approximately 10 |jLm thick, tips of adjacent tracheids appearing in cross section as intercellular spaces often lending an appearance of col- lenchyma to the xylem; radial pitting gener- Fig. 7-9. Agathoxylon lemonii: 7, Tangential section ally uniseriate, frequently biseriate, pits showing general size, shape, and arrangement of the rays (33X) (Holotype). 8, Tangential section illustrating ray slightly appressed, circular to horizontally size and shape. Note tangential tracheid pitting. (123X) elongate, 12-14 |xm diameter with 2.4-7.8 (Holotype). 9, Tangential section showing outline of ray |xm apertures; tangential pitting uniseriate and ray cells (495X) (Holotype). with pits same size as radial pitting, generally isolated; resin plates or plugs observed in many tracheids; axial parenchyma abundant, in Kansas. They also noted the presence of diffuse, with smooth thick walls and dark in- Brachyphyllum, which, although not com- tercellular contents; rays uniseriate, homocel- mon, was evidently a minor constituent of the lular, approximately six per millimeter, 20-70 fossil angiospermous swamp woodland flora of fxm wide, 10 (commonly 5 or 6) cells high, this formation. Possible conifer dominance in 30-150 |jLm high; ray cells vertically flattened the inland vegetation of the Dakota flora is and elongate horizontally, nearly twice as supported by a number of palynological stud- wide tangentially as high, often 50 |xm wide ies of this formation and rock units of equiva- tangentially by 30 \xm in vertical dimension lent age in North America (Pierce 1961, and 30-100 |xm (average 70 |jim) in radial di- Agasie 1969, Romans 1975, Retallack and mension; ray cells filled with dark cell con- Dilcher 1981). tents, ray cell walls approximately 3 |xm thick 562 Great Basin Naturalist Vol. 46, No. 3 and unpitted except at crossfield; crossfield wood (axillary) parenchyma and assigning pits commonly obscured by cell contents, ob- woods with parenchyma to Araucarioxylon. servable crossfields with 1-4, small (approxi- Edwards (1921) proposed using Dadoxylon for mately 5 |xm), slightly bordered pits with cir- araucariaceous wood that could not be related cular to oval included apertures. to e\\i\\ex Agathis or Araucaria . Some authors, Repository: Brigham Young University, such as Krausel and Jain (1963), Sah and Jain 5029 (Holotype). (1963), and Vogellehner (1964) followed Localities: 7 mi (11.2 km) east of Ferron, Gothan's (1905) recommendation that all Utah; U.S. Geol. Sui-v. Map: Desert Lake woods having an anatomical similarity to Quadrangle, SE 1/4, Sec 26, T20S, R8E Araucarineae or Cordaiteae should be placed (Holotype). Other specimen: 2.5 mi (4.02 km) into Dadoxylon as a single nomenclatural north of Westwater, Utah. unit. Krausel (1949) designated Araucarioxy- Horizon: Dakota Formation. lon as the genus for all woods related to

AgE: Lower Upper Cretaceous (Cenoma- Agathis OY Araucaria . Hartig (1848) instituted nian). the genus Agathoxylon for fossil having Etymology: The specific epithet is for Mr. "zellfasern" or axial parenchyma woods simi and Mrs. Frank Lemon of Moab, Utah, who lar to the living genus Agathis . The presence donated specimens for this study. of axial or wood parenchyma is the only char acter absent or rarely found in Araucaria Krausel and Jain (1963), in discussing Agath- Discussion oxylon remarked that Hartig had not given any details of his specimen. Sah and Jain The presence of araucarian tracheary pit- (1963) went further and suggested that the ting and of resin cysts, plugs, plates or spools "zellfasern" of the Hartig specimen were per- in Agathoxijlon lemonii indicate that it is allied haps resinous tracheids. According to Seward to the Araucariaceae. The Araucariaceae con- (1919), resin plates in tracheids are often in- sist of two extant genera, Araucaria De terpreted as end walls of axial parenchyma Jussieu with 18 species (De Laubenfels 1972) thus leading to erroneous reports of Agath and Agathis Salisbury composed of 13 species oxylon. Greguss (1955), Jane (1970), anc (Whitmore 1980). Fossil woods with araucar- Stockey (1982) considered the anatomical sep ian structure are abundant in the geologic aration between Agathis and Araucaria on thf record. They range in age from Carboniferous basis of wood anatomy to be not only difficul to Recent and have been assigned to many but nearly impossible. Greguss (1967) latei genera, including Araucarites Presl, Pinites reversed himself by pointing out that, of th Lindl. & Hutton sensu Presl, Dadoxyhm living species in the Araucariaceae, only thos( Endlicher, Araucarioxijlon Kraus, Agathoxij- in the genus Agathis contain true axial par lon Hartig, and Araiicariopitys ]e&ey . These enchyma, and subsequently he assigned tw( woods may also be related to Cordaioxylon

species to Agathoxylon . The fact that the Da Gr. Eury, Cordaites Unger, or early conifers kota wood under study bears axial par such as Lebachia Florin or Ernestodendron enchyma places it in Agathoxylon. Florin. Knowlton (1899), Penhallow (1907), Members of the genus Araucariopitys bea; Stopes (1914), Holden (1914), and Jeffrey short shoots, have resin ducts and abietinou: (1926) assigned Paleozoic araucarian woods to crossfield pitting, and are, therefore, not re Dadoxylon and reserved the name Araucari- lated to this wood from the Dakota Forma oxylon for Mesozoic and Tertiary materials. tion. Further, Seward (1919) proposed adding qualifying terms such as Araucarioxylon or Sou Cordaioxylon in parenthesis after Dadoxylon Comparison 1* whenever evidence supports such designa- tion. Torrey (1923) agreed somewhat with us- Of the living species oi Agathis, Agathoxy k

ing Araucarioxylon for Mesozoic and Ceno- Ion leinonii bears striking resemblance to th( (lie;

zoic woods and Dadoxylon for Late Paleozoic wood o( Agathis hypoleuca . It differs from A h types. However, he also separated them by hypoleuca in having higher rays (1-10 cell:' assigning Dadoxylon to fossil woods lacking high as opposed to 1-4 cells in A. hypoleuca) .

July 1986 TiDWELL, Thayn: Fossil Plant 563

fewer pits per crossfield (1-4 in A. lemonii, 4-8 wood parenchyma, but it diffiers from A. in A. hypoleuca\ and more abundant axial par- lejnonii in possessing septate tracheids, hav- enchyma. ing large crossfield pits with large lumens, and Dadoxijlon septentrionale Gothan (1905) dif- lacking tangential pitting. Dadoxylon (Arau- fers from A. leinonii in having typically 2-4 ellip- carioxylon) breveradiatum (Lignier) Seward tical to oblique crossfield pits and lacking tan- from the Cenomanian of Normandy has abun- gential pitting. Dadoxylon eocenum Chitaley dant resiniferous parenchyma, but it differs (1949) and Dadoxylon (Araucarioxylon) from A. lemonii by having higher rays (4-80, japonicum Shimakura (1936) have tangential pit- usually 10-40, cells high) and septate tra- ting, but both lack the xylem parenchyma of A. cheids. lemonii. Dadoxylon agathoides Krausel & Jain Dadoxylon (Araucarioxylon) novaezee- from the Jurassic of India is similar to the Dakota landii (Stopes) Seward from the Cretaceous of specimen. However, it lacks axial parenchyma, New Zealand has well-marked growth rings, has higher, narrower rays and has crossfield pits resin plates, and araucarian pitting. However, that are arranged in clusters. it differs from the Dakota Formation species Araucarioxylon texense Torrey has axial in its lack of wood parenchyma and having parenchyma and pitting similar to the speci- thick-walled tracheids on each side of the men from the Dakota Formation, although A. rays. texense has narrower rays and short shoots, There are a few reported species of Dadoxy- which A. lemonii lacks. Araucarioxylon hop- lon or Araucarioxylon from Japan that are pertonae Knowlton from the Cretaceous of similar to Agathoxylon lemonii. Dadoxylon the Black Hills is similar to A. lernonii in hav- (Araucarioxylon) sidugawaense Shimakura ing few pits per crossfield and low rays, but it (1936) from the Jurassic of Miyagi Prefecture lacks the characteristic axial parenchyma. is similar in possessing distinct growth rings, Holden (1914) mentioned an araucarian type similar radial pitting, tangential pitting, and, wood from the Cretaceous of New Jersey (Rar- in the presence of xylem, parenchyma. But D. itan Formation) whose pith contains large (A), sidugawaense differs from the former masses of stone cells similar to those in living species in having circular, alternate tangential Agathis but lacks wood parenchyma. Dadoxy- pits and simple crossfield pits, whereas the lon novehoracense (Holl. & Jeff.) from the tangential pits of A. lemonii are the same size mid-Cretaceous beds of Staten Island lacks as the pits on the radial walls. These tangential definite growth rings and has uniseriate tra- pits are isolated rather than contiguous, and cheary pitting. These characters are similar to the crossfield pits of the latter species are A. ivyomingense Andrews and Pannell (1942) slightly bordered rather than simple. Two from Cretaceous strata of Gros Wntre Canyon Lower Cretaceous species from Japan, Arau- in Wyoming. Araucarioxylon wyomingen.se carioxylon hujinamien.se Ogura (1960) from lacks the wood parenchyma and tangential Wakayama and Chiba and A. pseudo-huji- pitting that separates this species from A. namien.se Nishida and Oishi (1982) from the lemonii Kwanto Mountain, both differ from A. lemonii Among the species belonging to this genus in possessing tylosislike structures in their tra- described from the Mesozoic of Africa, the cheids and in lacking wood parenchyma. following four possess wood parenchyma Araucarioxylon nihongii Nishida and Nishida

(Gazeau 1969): D. (A. ) aegyptiacum Unger (1984) is quite similar to this Dakota Forma-

(1859), D. (A. ) paumieri Loubiere (1935), D. tion species. The Japanese species, however,

(A.) septatum Boureau (1951) from the Sahara has 3-5 rows of pits on its tracheid walls, has Soudanais, and D. (A.) koufraense Batton shorter parenchyma cells, and lacks tangential (1965) from the continental series of Libya. pitting. They differ from A. lemonii, in general, by Agathoxylon species similar to Agathoxylon having different ray height, different tra- lemonii include A. australe Evans, A. hun- cheary pitting, and, with some, having septa- garicum (Andreanszky) Greguss, and A. mec- tions in their tracheids. seken.se Greguss. Agathoxylon au.strale is a Dadoxylon alpinum Lemoigne (1966) from Pliocene fossil from New Zealand that has the Jurassic of the Bassin de la Durance has vestured pits and lacks axial parenchyma. 564 Great Basin Naturalist Vol. 46, No. 3

Evans (1934) originally assigned this species angiosperms, in close spatial association with to Agathis and later renamed it Agathoxylon the actual swamp vegetation. The coarser australe (Evans 1937). Krausel and Jain (1963) elastics of modern distributary channels and noted that Agathoxylon oustrale is very simi- coastal lagoons usually include a mixed assem- lar to living Agathis austrails . Agathoxijlon blage derived primarily from the lower coastal mecsekense from the Jurassic of Hungary has plain but also including wood that may have high, narrov^ rays and commonly has triseriate been transported for greater distances than is pitting. Although the description given for A. typically the case with the angiosperm leaves hungariciim is incomplete, it appears to have or conifer needles in such deposits. The higher rays and more pits per crossfield than coarser sandstone in which the specimens of our specimen. Agathoxijlon lemonii were collected suggests the possibility that they were transported from a well-drained habitat occurring some- Paleoecology where along the lower delta plain associated with the deposition of the Dakota Formation. The extant genus Agathis may be found growing in association with the fern Matonia in the tropical uplands of the Malay Peninsula Acknowledgments and the island of Borneo (Seward 1899). Mor- phologically, the fossil genus Matonidium is The authors wish to express their apprecia- similar to the extant Matonia (Berry 1919). tion to S. R. Rushforth of Brigham Young Matonidium occurs in abundance in the Da- University, Provo, Utah; S. R. Ash of Weber kota Formation near Westwater, Utah, a lo- State College, Ogden, Utah; Greg Retallack cality quite close to a collecting site for Agath- of the Univesity of Oregon, Eugene, Oregon; oxijlon lemonii. Mahabale (1954) considered and R. E. Taggart of Michigan State Univer- matoniaceous ferns to be among a select group sity, East Lansing, Michigan, for their review of ferns that served as reliable indicators of of the manuscript. subtropical to tropical paleoclimate; the presence of abundant Matonidium is, therefore, Literature Cited suggestive of a similarly warm, climatic regime during the deposition of this formation Acasie, J M 1969. Late Cretaceous palynomorphs from in this area. This reconstruction is supported northeastern Arizona. Micropalaeontology 15: by Roman's (1972) study of the schizeaceous 13-30. spores of the Dakota Formation and other Andrews, H N , and E Pannell. 1942. A fossil araucarian wood from western Wyoming. Ann. Missouri reconstructions that have emphasized the Bot. Card. 29; 283-285. subtropical to tropical nature of the regional Batton. G 1965. Contribution a letude anatomique et fossil assemblage (Rushforth 1971). biostratigraphique de la flora du Continental in- The precise community assignment for A. terclaire saharien. Publ. Centre de Rech. sone lemonii is more elusive. Agasie (1969), Rush- arides.-CRNS, ser. Geol. 6: 12-95. Berry. E 1919. A new Matonidium from Colorado, forth (1971), and May and Traverse (1973) all W with remarks on the distribution of the Matoni- suggested that the Dakota Formation was de- aceae. Bull. Torrey Bot. Club 46(8): 285-294. posited on a wet, low-lying landscape in close BouREAU, E. 1951. Etude Paleoxylologique du Sahara. proximity to drier uplands. The Matonidium (Xlll): Sur une nouvelle espece du Continental leaf material occurs in an ash layer associated intercalaire du Sahara Soudanais: Dadoxylon (Araiicarioxijlon)septatumn. sp. Bull. Mus. Natl. with a coal bed at the Westwater site. The Hist. Natr. 231-237. swamps of the Dakota Formation, which pro- 23(1): Brown, R W 1950. Cretaceous plants from southwestern duced the peat that is the original source of Colorado. U.S. Geol. Surv. Prof Paper 221-D: the coals of the region, apparently supported a 45-66. diverse tree and shrub flora in which ferns Chitaley, S D 1949. On a new species o( Dadoxylon, were probable understory elements (Retal- Dadoxylon eocenum sp. nov. from the district of Chhindwara, C. P., India. Indian Bot. Soc. lack and Dilcher 1981). In such situations, J. 28(4): 227-237. however, microtopographic variability can re- De Laubenfels. D J 1972. Flore de la Nouvelle- sult in a complex vegetation mosaic with Caledonie et dependances. 4. Gymnospermes. somewhat drier sites, possibly dominated by Mus. Natl. Hist. Natr. 168 pp. .

July 1986 TiDWELL, Thayn: Fossil Plant 565

DiLCHER. D L 1979. Early angiosperm reproduction: an Lemoigne, Y , andG. Demarcq. 1967. Nouvelle espece introductory report. Rev. Palaeob. Palyn. 27: de Dadoxylon a tracheide septees provenant du 291-328. Wealdien de Feron-Glageon (Nord). Bull. Soc. DiLCHER. D L., W. L. Crepet, C D Beeker. and H C Geol. de France 9: 53-56. Reynolds 1976. Reproductive and vegetative Lesquereux, L. 1874. Contributions to the fossil flora of

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DiLCHER, D. L., F Potter, and H. C Reynolds 1978. 1883. The fossil flora of the Western Territories. of Cretaceous an- Preliminary account Middle Part III. The Cretaceous and Tertiarv floras. Rept. giosperm remains from the interior of North U.S. Geol. Surv. 8:1-283. America. Cour. Forsch.-lnst. Senckenberg 30: 1892. The flora of the Dakota Group. Monogr. 9-15. U.S. Geol. Surv. 17: 1-256. Edwards. W N 1921. Fossil coniferous wood from Maharale, T S. 1954. Ferns and palms as indicators of Kerguelen Island. Ann. Bot. 35: 609-617. climate and paleo-climate. Palaeobotanist 3: Evans, W. P. 1934. Microstructure of New Zealand lig- 33-37. nites III. New Zealand J. Sci. Tech. 15(6): M.\y, F. E.. and a. Traverse. 1973. Palynology- of the 365-385. Dakota Sandstone (Middle Cretaceous) near 1937. Notes on the flora which yielded the Ter- Bryce Canyon National Park, southern Utah. Geo- tiary lignites of Canterbury', Otago and South science and Man 7: 57-64. Land. New Zealand J. Sci. Tech. 19: 190.

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