The Lapara Creek Fauna, Clarendonian of south Texas

 

     Fossil vertebrates from the Beeville area in south Texas have been known since the late 1930’s when a large collection was made by the Works Project Administration (WPA) project under the direction of scientists at the University of Texas.  These fossils have been described in numerous publications including Sellards (1940a), Quinn (1955), Wilson (1956, 1960), Patton (1969, 1971, 1973), Forsten (1975), Webb and Hulbert (1986), Hulbert (1987, 1988).  Each of these publications deals with one or a few taxonomic groups and no complete synthesis of the entire fauna exists.  Early publications considered the Lapara Creek Fauna to be Pliocene, but with refinement of the geologic time scale and North American Land Mammal ages, the Lapara Creek Fauna is now considered middle Miocene (Clarendonian).  The Goliad Formation can be correlated in the subsurface with marine strata that are Serravalian in age (Galloway et al., 1986).

 

     The Lapara Creek Fauna is the most extensive Clarendonian fauna from the Texas Gulf Coast and therefore provides critical information for our understanding of the biota, ecology and paleoenvironment that existed in Texas during the Miocene.  Previous work has focused on specific groups of fossil mammals from the Lapara Creek Fauna, but no comprehensive review of the entire fauna is available.

 

     Tedford et al. (1987) suggest that the Lapara Creek Fauna can be divided into two local faunas, the Bridge Ranch local fauna and the Farish Ranch local fauna.  This distinction is based in part on their interpretation of the horses and general faunal similarity with the Burge and Minnechaduza faunas from Nebraska (Webb, 1969).  They also note similarities between the younger Farish Ranch local fauna (within which they include materials from the Buckner Ranch locality) and the fauna from the McAdams Ranch Quarry in the lower Clarendon beds of northern Texas.  Tedford et al. (1987) argue that these correlations are consistent with the artiodactyls, but that it is difficult to use Quinn’s (1955) discussion of the equids. Forsten (1975) attempted to revise Quinn’s equid taxonomy.

 

      Tedford et al. (2004) maintain this two local fauna scheme and show the Lapara Creek Fauna as including the Cl1 Bridge Ranch local fauna and the Cl2 Farish Ranch local fauna, both from the Lapara Member of the lower Goliad Formation.  They show the Labahia Mission Fauna as Hemphillian in age from the Labahia Member of the Goliad.  Based on their regional analyses, Tedford et al. (2004) suggest that the Lapara Creek Fauna is roughly equivalent to the Agricola Fauna from Florida (Morgan, 1994), the Round Mountain Quarry of the Chamita Formation in the Rio Grande Rift (Galusha and Blick, 1971), the Clarendon Fauna of the Texas panhandle (Schultz, 1990), and the Burge and Minnechaduza Faunas of Nebraska (Webb, 1969).

 

      No direct radiometric or paleomagnetic control exists to constrain the age of the Goliad Formation.  Targeted paleomagnetic sites associated with key vertebrate localities may prove useful to evaluate relative ages and perhaps correlation with the magnetic polarity time scale.  Detrital zircon geochronology will also be used to investigate the potential presence of depositional age grains.

 

     In Wilson’s (1956) review of Miocene stratigraphy and vertebrate fossils in Texas, he followed Plummer (1933) using a three-member subdivision of the Goliad Formation placing the Lapara Creek Fauna in the Lapara Member and the Labahia Mission local fauna in the Labahia Member.   He considered the Lapara Member to be Upper Miocene and the Labahia Member to be Upper Pliocene.  Hoel (1982) reviewed the stratigraphy of the Goliad Formation and concluded that the three members proposed by previous workers were not regionally meaningful and could not be recognized in the subsurface.  Hoel (1982) recognizes fluvial and floodplain facies of the Goliad Formation that he separates into four depositional systems.  Each of these systems reflects different fluvial axes that generally correlate with the modern Rio Grande, Nueces, San Antonio/Guadalupe and Colorado Rivers.  The area in Bee and Live Oak Counties associated with the Lapara Creek Fauna is associated with the Mathis depositional system.  Hoel (1982) recognized two major channel axes within the Mathis system that he believed were derived from a source area in the Edwards Plateau region of central Texas.  The Mathis depositional system is interpreted to reflect broad, shallow, braided streams that were flanked by complex splay deposits and adjacent floodplain.

 

Goliad Formation, Blanco Creek

 

     In the area near Beeville, exposures of the Goliad Formation are generally limited to creek beds, quarries, and road cuts and cannot be easily correlated between localities.  It is difficult at present to support the Cl1 - Cl2 local fauna interpretation of Tedford et al. (1987, 2004) based on physical stratigraphy especially given the complex facies relationships documented by Hoel (1982).  It is possible that the Ten Mile Waterhole Creek and Bridge Ranch localities are from stratigraphically lower in the Goliad Formation than the Farish and Buckner Ranch localities based on regional structural trends.  According to the WPA field notes, the Buckner Ranch local fauna was collected from “light clay” while the Farish Ranch local fauna was primarily located in sandstones and conglomerates.  The Bridge Ranch fossils were collected from “pink clay conglomerates and sandstones”, while the stratigraphy associated with the Ten Mile Waterhole Creek fossils is only referred to as the Lapara Formation.

 

     Based on information in the VPL database and collection labels, the Lapara Creek Fauna includes >50 taxa.  All identifications are being reevaluated.  Although much attention has been directed toward the horses (Quinn (1955), Forsten (1975), Hulbert (1987, 1988), Webb and Hulbert (1986)), there is still significant need to enforce a consistent taxonomy across the entire collection.  Sellards (1940) described Gnathabelodon buckneri as a new species of mastodon and states that 15 skulls of both immature and adult animals were collected along with a large amount of post-cranial material.  However, in his 1940 paper, Sellards illustrates material from only three specimens and includes no post-cranial material. The lack of small mammals is also clear from the faunal list and is something we hope to rectify with additional fieldwork and screen washing.

 

 

                                                                

                                                                       Extracting a Gnathabelodon femur 1939.

 

References

 

Baskin, J.A. and R.C. Hulbert, 2012, A late Clarendonian local fauna from the Goliad Formation of south Texas. Paludicola, 8(4):187-193.

 

Forsten, A., 1975, The fossil horses of the Texas Gulf Coastal Plain: a revision. Texas Memorial Museum, Pierce-Sellards Series, 22:1-86.

 

Galloway, W.E., L.A. Jirik, R.A. Morton, and J.R. DuBar, 1986, Lower Miocene (Fleming) depositional episode of the Texas coastal plain and continental shelf: structural framework, facies, and hydrocarbon resources, University of Texas Bureau of Economic Geology, Report of Investigations No. 150.

 

Galusha, T. and Blick, J. C., 1971, Stratigraphy of the Santa Fe Group, New Mexico. Bulletin of the American Museum of Natural History, 144:1-128.

 

Hoel, H.D., 1982, Goliad Formation of the South Texas Gulf Coastal Plain: Regional genetic stratigraphy and uranium mineralization, unpublished M.A. thesis, University of Texas, 173 p.

 

Hulbert, R. C., Jr., 1987, Late Neogene Neohipparion (Mammalia, Equidae) from the Gulf Coastal Plain of Florida and Texas. Journal of Paleontology, 61:809-830.

 

Hulbert, R. C., 1988, Calippus and Protohippus (Mammalia, Perissodactyla, Equidae) from the Miocene (Barstovian early Hemphillian) of the Gulf Coastal Plain. Bulletin of the Florida State Museum, Biological Sciences, 32:221-340.

 

Morgan, G. S., 1994, Miocene and Pliocene Marine Mammal Faunas from the Bone Valley Formation of Central Florida. p. 239-268 in A. Berta & T.A. Deméré, eds. Contributions in Marine Mammal Paleontology Honoring Frank C. Whitmore, Jr. Proceedings of the San Diego Natural History Society Number 29.

 

Patton, T.H., 1969, Miocene and Pliocene artiodactyls, Texas Gulf Coastal Plain. Bulletin Florida State Museum Biological Science, 14(2):115-226.

 

Patton, T.H. and B.E. Taylor, 1971, The Synthetoceratinae (Mammalia, Tylopoda, Protocertaidae). Bulletin of the American Museum of Natural History, 145(2): 123-218.

 

Patton, T.H. and B.E. Taylor, 1973, The Protocertatinae (Mammalia, Tylopoda, Protocertatidae) and the systematics of the Protoseratidae. Bulletin of the American Museum of Natural History, 150(4): 349-413.

 

Quinn, J. H., 1955, Miocene Equidae of the Texas Gulf Coastal Plain. Bureau of Economic Geology,

University of Texas Publication No. 5516, 102 p.

 

Schultz, G.E., 1990, The Clarendonian faunas of the Texas and Oklahoma Panhandles. P. 83-94 in Gustavson, T.C., ed., Tertiary and Quaternary stratigraphy and vertebrate paleontology of parts of northwestern Texas and eastern New Mexico, University of Texas Bureau of Economic Geology, Guidebook 24.

 

Sellards, E. H., 1940a, New Pliocene mastodon. Geological Society of America Bulletin, 51:1659-1664.

 

Sellards, E.H., 1940b, Pleistocene artifacts and associated fossils from Bee County, Texas. Geological Society of America Bulletin, 51:1627-1658.

 

Tedford, R.H., Galusha, T., Skinner, M.F., Taylor, B.E., Fields, R.W., Macdonald, J.R., Rensberger, J.M., Webb, S.D., and Whistler, D.P., 1987, Faunal succession and biochronology of the Arikareean through

Hemphillian interval (late Oligocene through earliest Pliocene Epochs) in North America; p. 153-210, in M.O. Woodburne, (editor), Cenozoic Mammals of North America, Geochronology and Biostratigraphy: University of California Press, Berkeley, CA.

 

Tedford, R. H., L. B. Albright, III, A. D. Barnosky, I. Ferrusquia-Villafranca, R. M. Hunt, Jr., J. E. Storer, C. C. Swisher, III, M. R. Voorhies, S. D. Webb, and D. P. Whistler. 2004. Mammalian biochronology of the Arikareean through Hemphillian interval (late Oligocene through early Pliocene epochs). p. 169–231, in M. O. Woodburne (editor), Late Cretaceous and Cenozoic mammals of North America: biostratigraphy and geochronology. Columbia University Press, New York.

 

Webb, S. D., 1969, The Burge and Minnechaduza Clarendonian mammalian faunas of north central

Nebraska. University of California Publications in Geological Sciences, 78:1-191.

 

Webb, S.D., and R. C. Hulbert, 1986, Systematics and evolution of Pseudhipparion (Mammalia, Equidae) from the Late Neogene of the Gulf Coastal Plain and the Great Plains. p. 237-272, in K. Flanagan and J. A. Lilligraven (eds.), Vertebrates, Phylogeny, and Philosophy. University of Wyoming Press, Laramie.

 

Wilson, J. A.,1956, Miocene formations and vertebrate biostratigraphic units, Texas Coastal Plain. Bulletin of the American Association of Petroleum Geologists, 40:2233-2246.

 

Wilson, J.A., 1960, Miocene carnivores, Texas Coastal Plain, Journal of Paleontology, 34(5):983-1000.

 

 

WPA excavation at the Buckner Ranch Site: ~1939.

 

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Paleontology of the Late Jurassic Malone Formation

 

      Outcrops of Jurassic age sedimentary rocks are extremely rare in Texas.  One of the few known localities is in the Malone Mountains  located near the town of Sierra Blanca in west Texas.  Although fossil invertebrates have been known for over a century from the Malone Formation, only brief comments have been made about plant and vertebrate fossils. No vertebrate fossils have been previously described from Jurassic strata in Texas so staff from UT and SMU initiated a new field program in 2015 that identified abundant invertebrate fossils, plant fossils, and rare vertebrate fossils.  We have obtained a paleontological use agreement from the Texas General Land Office for Texas State Lands in the Malone Mountains.  We have also obtained permission from private landowners in the northern Malone Mountains to collect fossils from the Malone Formation.  All fossils collected will be housed at the Vertebrate Paleontology Laboratory, University of Texas.

 

                    

 

Bone fragments and plant material identified during 2015 reconnaissance work in the Malone Formation.

 

      Cragin (1897) published “Discovery of Marine Jurassic Rocks in Southwestern Texas”.  Based on preliminary collections of invertebrate fossils, he recognized the significance of the Malone Formation as a very rare occurrence of Jurassic strata exposed in Texas.  Cragin (1905) (with contributions from Stanton) described the invertebrate fauna from the Malone Formation in greater detail and also noted the rare occurrence of vertebrate fossils as well.  In his faunal list for he includes “Pycnodont fish tooth, Cycloid fish scales, and Enaliosaur (fragments of bones, indicating animal of considerable size)”.  Cragin (1905) concluded that the invertebrate fauna clearly indicated a Jurassic age for the Malone Formation with strongest affinities to the Kimmeridgian and Tithonian.  Although he noted the presence of vertebrate bone fragments, apparently none of these were collected, none were figured, and no indication of accession into a museum collection has been found.

 

      Albritton (1937) described fossil foraminifera from the lower member of the Malone Formation that he interpreted as Late Jurassic in age although both of the taxa were new species of the genus Robulus.  Albritton (1938) described the Malone Formation as a sequence of conglomerate, sandstone, sandy shale, siltstone, gypsum and limestone.  He further recognized a lower member with a higher abundance of thin-bedded, clastic strata, and an upper member characterized by the predominance of limestone.  Albritton (1938) documented a large variation in thickness of the Malone Formation from 150 feet in the east to 1060 feet in the northwest Malone Mountains.  He also documented an extensive list of invertebrates (many of which were previously described by Cragin (1905)) from the Malone Formation including 56 species of pelecypods, 18 gastropods, and 15 cephalopods.  He interpreted the ammonites to be the best evidence for correlation of the Malone Formation with Jurassic strata in Mexico.  Albritton noted that ammonites were most common in the upper 100 feet of the lower member and in the upper 25 feet of the upper member.  He concluded that the Malone Formation was Kimmeridgian and Tithonian in age base on the distribution of ammonites.

 

      Imlay (1940) described fossil pelycypods from Mexico and compared them to the fauna from the Malone Formation in the Malone Mountains.  He agreed with Cragin (1905) and Albritton (1937, 1938) that the fauna was most likely of Late Jurassic age and correlated the formation with the La Casita Formation of the Saltillo-Torreon area.

 

      In their USGS Professional Paper on the geology of the Sierra Blanca region, Albritton and Smith (1965) reviewed the stratigraphic and paleontological evidence for the age of the Malone Formation and concluded that it is a Late Jurassic sequence consisting of two members.  The lower member was characterized as mostly sand shale, siltstone, sandstone, and conglomerate while the upper member was mostly limestone.  Our observations in the northern and eastern Malone Mountains indicate relatively abundant limestone in the upper part of the lower member.  The contact between these two members was described by Albritton and Smith (1965) as conformable and transitional and they recognized that the two members were in part, age-equivalent facies.  The ammonites Idoceras and Kossmatia from the lower and upper members were interpreted to indicate Kimmeridgian and Tithonian ages for these strata.  The Malone Formation changes thickness rapidly and is absent in the adjacent Finlay Mountains to the north.  Huffington (1943) mapped a very thin interval (50-75 feet) of limestone, shale, and chert-pebble conglomerate that he interpreted as the upper member of the Malone Formation in the northwestern Quitman Mountains just south of I-10.

 

      The only vertebrate fossils mentioned by Albritton and Smith (1965) were those previously noted by Cragin (1905) and Albritton (1938).  Fossil plants are also mentioned, but only described as “driftwood”.  Cragin (1905) noted the presence of the boring clam Martesia maloniana in some of the plant fossils.

 

      King (1969) identified Kossmatia kingi from the Malone Formation and assigned at least part of that unit to the middle Tithonian (Kossmatia rancheriaensis zone of Imlay, 1984).

 

      Berge (1981) reported on the geology of the Malone Mountains in his unpublished MS thesis (Univ. Texas).  He interpreted the lower member of the Malone Formation to represent deposits of a fan-delta system and recognized “sheetflood” (clast-supported conglomerate), “debris-flow” (matrix-supported conglomerate), “sandstone” and “distal” facies.  Berge (1981) interpreted limestone within the Malone Formation to represent sub-tidal through supra-tidal facies.   His interpretation of the tectonic evolution of the Malone Mountains included Late Triassic(?) faulting associated with the formation of the Chihuahua Trough, Laramide folding and thrusting, late Laramide left-lateral strike-slip folding, and finally Basin-and-Range faulting during the Tertiary.  More recent syntheses of the tectonic evolution of this region suggest that oblique extension associated with the formation of the Chihuahua Trough occurred during the Late Jurassic (Haenggi and Muehlberger, 2005).

 

Detrital Zircon Geochronology

 

      U/Pb ages were obtained from detrital zircons in two samples from the lower Malone Formation.    MM002 was collected from calcareous sandstone approximately 25 feet above the base of the Malone Formation.  Of the 100 detrital zircons analyzed, all U/Pb ages are Permian and older.  19% are Paleozoic, 79% are Proterozoic and only 2% are Archean.  The most abundant age population yields Grenville ages (1000 – 1100 Ma) with a statistically significant age peak at 1040 Ma.

 

      MM001 was collected from calcareous sandstone approximately 55 feet stratigraphically above MM002 in the lower Malone Formation.  Of the 99 detrital zircons analyzed, 8 grains are Mesozoic in age and the youngest statistically significant age peak was observed at 247 Ma (Triassic).  Three grains produced Jurassic ages (151 +/- 2, 167 +/- 3, 174 +/- 2 Ma).  Although only a single grain, the 151 +/-2 Ma age is consistent with the depositional age of the lower Malone Formation based on ammonites as described above.  13% of the detrital zircons yield Paleozoic ages, 75% are Proterozoic, and again, only 2% are Archean.  As with MM002, the most abundant population is Grenville in age with a statistically significant age peak at 1033 Ma.

 

                                       

 

Age probability diagram for 2 samples from the lower Malone Formation.

 

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Fossil Vertebrates of Texas

 

     “Fossil Vertebrates of Texas” is a book project still in its infancy.  The goal is to produce a scientifically accurate and useful overview for a broad audience.  I plan to include high quality photographic imagery of geology and fossils, historical photos and documents, and citations and references.  The book will discuss what we know and don’t know (what are the big questions).  Sections currently under construction include a historical perspective of paleontologists and institutions, the paleogeographic evolution of Texas as a framework for understanding the distribution of fossils in space and time (collaboration with Ron Blakey), as well as key fossils and localities organized by geologic age.

      I hope the book will successfully educate the public at large, inspire students to go into science, sit on coffee tables and in reference libraries, and be useful as a promotional tool for current Texas institutions of paleontology.