<?xml version="1.0" encoding="ISO-8859-1"?><article xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
<front>
<journal-meta>
<journal-id>1026-8774</journal-id>
<journal-title><![CDATA[Revista mexicana de ciencias geológicas]]></journal-title>
<abbrev-journal-title><![CDATA[Rev. mex. cienc. geol]]></abbrev-journal-title>
<issn>1026-8774</issn>
<publisher>
<publisher-name><![CDATA[Universidad Nacional Autónoma de México, Instituto de Geología]]></publisher-name>
</publisher>
</journal-meta>
<article-meta>
<article-id>S1026-87742005000100039</article-id>
<title-group>
<article-title xml:lang="en"><![CDATA[Towards a standard ammonite zonation for the Aptian (Lower Cretaceous) of northern Mexico]]></article-title>
<article-title xml:lang="es"><![CDATA[Hacia una zonación estándar de ammonites para el Aptiano (Cretácico Inferior) del norte de México]]></article-title>
</title-group>
<contrib-group>
<contrib contrib-type="author">
<name>
<surname><![CDATA[Barragán-Manzo]]></surname>
<given-names><![CDATA[Ricardo]]></given-names>
</name>
<xref ref-type="aff" rid="Aff"/>
</contrib>
<contrib contrib-type="author">
<name>
<surname><![CDATA[Méndez-Franco]]></surname>
<given-names><![CDATA[Ana Laura]]></given-names>
</name>
<xref ref-type="aff" rid="Aff"/>
</contrib>
</contrib-group>
<aff id="Af1">
<institution><![CDATA[,Universidad Nacional Autónoma de México Instituto de Geología ]]></institution>
<addr-line><![CDATA[ ]]></addr-line>
<country>Mexico</country>
</aff>
<pub-date pub-type="pub">
<day>00</day>
<month>00</month>
<year>2005</year>
</pub-date>
<pub-date pub-type="epub">
<day>00</day>
<month>00</month>
<year>2005</year>
</pub-date>
<volume>22</volume>
<numero>1</numero>
<fpage>39</fpage>
<lpage>47</lpage>
<copyright-statement/>
<copyright-year/>
<self-uri xlink:href="http://www.scielo.org.mx/scielo.php?script=sci_arttext&amp;pid=S1026-87742005000100039&amp;lng=en&amp;nrm=iso"></self-uri><self-uri xlink:href="http://www.scielo.org.mx/scielo.php?script=sci_abstract&amp;pid=S1026-87742005000100039&amp;lng=en&amp;nrm=iso"></self-uri><self-uri xlink:href="http://www.scielo.org.mx/scielo.php?script=sci_pdf&amp;pid=S1026-87742005000100039&amp;lng=en&amp;nrm=iso"></self-uri><abstract abstract-type="short" xml:lang="en"><p><![CDATA[Abstract Detailed data on twenty-seven species of ammonites identified in three stratigraphic sections of northern Mexico, allow further refinement of the Aptian ammonite biozonations of previous authors. Four formal ammonite biozones are proposed. Dufrenoyia justinae Taxon-Range-Zone for the uppermost part of the lower Aptian (Bedoulian), Epicheloniceras cf. subnodosocostatum/Acanthohoplites acutecosta Interval Zone representative of the middle Aptian (Gargasian), and Acanthohoplites aschiltaensis and Hypacanthoplites cf. leanzae Taxon-Range -Zones, spanning the upper Aptian (Clansayesian). The ammonite zonation proposed represents the advancements on the development of a standard scheme towards a reliable correlation with the biozonal scheme of England and the ammonite zonal standard of the Mediterranean area.]]></p></abstract>
<abstract abstract-type="short" xml:lang="es"><p><![CDATA[Resumen Estudios detallados de veintisiete especies de ammonites provenientes de tres secciones estratigráficas del norte de México, permiten redefinir los esquemas biozonales del Aptiano, establecidos previamente por otros autores para el área, con base en la distribución vertical de estos macrofósiles. En este trabajo se proponen cuatro biozonas formales de ammonites. La Zona de Rango Dufrenoyia justinae para la parte terminal del Aptiano inferior (Bedouliano), la Zona de Intervalo Epicheloniceras cf. subnodosocostatum/Acanthohoplites acutecosta representativa del Aptiano medio (Gargasiano) y las Zonas de Rango Acanthohoplites aschiltaensis e Hypacanthoplites cf. leanzae, características del Aptiano superior (Clansayesian). La biozonación de ammonites propuesta representa los avances en el desarrollo de un esquema estandarizado con miras a realizar correlaciones más precisas con los esquemas biozonales desarrollados para Inglaterra y el área Mediterránea.]]></p></abstract>
<kwd-group>
<kwd lng="en"><![CDATA[biostratigraphy]]></kwd>
<kwd lng="en"><![CDATA[ammonites]]></kwd>
<kwd lng="en"><![CDATA[Aptian]]></kwd>
<kwd lng="en"><![CDATA[Mexico]]></kwd>
<kwd lng="es"><![CDATA[bioestratigrafía]]></kwd>
<kwd lng="es"><![CDATA[ammonites]]></kwd>
<kwd lng="es"><![CDATA[Aptiano]]></kwd>
<kwd lng="es"><![CDATA[México]]></kwd>
</kwd-group>
</article-meta>
</front><back>
<ref-list>
<ref id="B1">
<nlm-citation citation-type="book">
<person-group person-group-type="author">
<name>
<surname><![CDATA[Amos]]></surname>
<given-names><![CDATA[S.]]></given-names>
</name>
</person-group>
<source><![CDATA[International Stratigraphic Guide. A guide to stratigraphic classification, terminology, and procedure]]></source>
<year>1994</year>
<edition>second</edition>
<page-range>214</page-range><publisher-loc><![CDATA[Boulder, Colorado ]]></publisher-loc>
<publisher-name><![CDATA[The Geological Society of America]]></publisher-name>
</nlm-citation>
</ref>
<ref id="B2">
<nlm-citation citation-type="journal">
<person-group person-group-type="author">
<name>
<surname><![CDATA[Anthula]]></surname>
<given-names><![CDATA[D.J.]]></given-names>
</name>
</person-group>
<article-title xml:lang=""><![CDATA[Über die Kreidefossilien des Kaukasus mit einem allegemeinen Ueberblick über die Entwicklung der Sedimentär-bildungen des Kaukasus]]></article-title>
<source><![CDATA[Beitraege zur Palaeontologie und Geologie Oesterreich-Ungarns und des Orients]]></source>
<year>1900</year>
<volume>12</volume>
<page-range>54-159</page-range></nlm-citation>
</ref>
<ref id="B3">
<nlm-citation citation-type="book">
<person-group person-group-type="author">
<name>
<surname><![CDATA[Barragán]]></surname>
<given-names><![CDATA[R.]]></given-names>
</name>
</person-group>
<source><![CDATA[Ammonite biostratigraphy, lithofacies variations, and paleoceanographic implications for Barremian-Aptian sequences of northeastern Mexico]]></source>
<year>2000</year>
<page-range>296</page-range><publisher-loc><![CDATA[Miami, U.S.A. ]]></publisher-loc>
<publisher-name><![CDATA[Florida International University]]></publisher-name>
</nlm-citation>
</ref>
<ref id="B4">
<nlm-citation citation-type="journal">
<person-group person-group-type="author">
<name>
<surname><![CDATA[Barragán]]></surname>
<given-names><![CDATA[R.]]></given-names>
</name>
</person-group>
<article-title xml:lang=""><![CDATA[Sedimentological and paleoecological aspects of the Aptian transgressive event of Sierra del Rosario, Durango, northeast Mexico]]></article-title>
<source><![CDATA[Journal of South American Earth Sciences]]></source>
<year>2001</year>
<volume>14</volume>
<page-range>189-202</page-range></nlm-citation>
</ref>
<ref id="B5">
<nlm-citation citation-type="book">
<person-group person-group-type="author">
<name>
<surname><![CDATA[Bogdanova]]></surname>
<given-names><![CDATA[T.N.]]></given-names>
</name>
</person-group>
<source><![CDATA[The Lower Aptian and its boundaries in the western and southern Turkmenistán (in russian)]]></source>
<year>1971</year>
<page-range>29</page-range><publisher-loc><![CDATA[Moscow ]]></publisher-loc>
<publisher-name><![CDATA[University of Moscow]]></publisher-name>
</nlm-citation>
</ref>
<ref id="B6">
<nlm-citation citation-type="journal">
<person-group person-group-type="author">
<name>
<surname><![CDATA[Bogdanova]]></surname>
<given-names><![CDATA[T.N.]]></given-names>
</name>
</person-group>
<article-title xml:lang=""><![CDATA[Deshayesites tuarkyricus Zone: the lowermost Aptian of Turkmenistan (in russian)]]></article-title>
<source><![CDATA[Ezhegodnik Vses Paleontologicheskii Obshchestva]]></source>
<year>1983</year>
<volume>26</volume>
<page-range>128-47</page-range></nlm-citation>
</ref>
<ref id="B7">
<nlm-citation citation-type="journal">
<person-group person-group-type="author">
<name>
<surname><![CDATA[Bogdanova]]></surname>
<given-names><![CDATA[T.N.]]></given-names>
</name>
<name>
<surname><![CDATA[Tovbina]]></surname>
<given-names><![CDATA[S.Z.]]></given-names>
</name>
</person-group>
<article-title xml:lang=""><![CDATA[On development of the Aptian Ammonite zonal standard for the Mediterranean region]]></article-title>
<source><![CDATA[Géologie Alpine]]></source>
<year>1994</year>
<volume>20</volume>
<page-range>51-9</page-range></nlm-citation>
</ref>
<ref id="B8">
<nlm-citation citation-type="journal">
<person-group person-group-type="author">
<name>
<surname><![CDATA[Breistroffer]]></surname>
<given-names><![CDATA[M.]]></given-names>
</name>
</person-group>
<article-title xml:lang=""><![CDATA[Sur les zones d&#8217;ammonites de l&#8217;Albian de France et d&#8217;Angleterre]]></article-title>
<source><![CDATA[Travaux du Laboratoire de Géologie de l&#8217;Université de Grenoble]]></source>
<year>1947</year>
<volume>26</volume>
<page-range>1-88</page-range></nlm-citation>
</ref>
<ref id="B9">
<nlm-citation citation-type="journal">
<person-group person-group-type="author">
<name>
<surname><![CDATA[Burckhardt]]></surname>
<given-names><![CDATA[C.]]></given-names>
</name>
</person-group>
<article-title xml:lang=""><![CDATA[Faunas del Aptiano de Nazas (Durango)]]></article-title>
<source><![CDATA[Instituto de Geología de México, Boletín]]></source>
<year>1925</year>
<volume>45</volume>
<page-range>71</page-range></nlm-citation>
</ref>
<ref id="B10">
<nlm-citation citation-type="book">
<collab>Bureau de Recherches Géologiques et Minieres (BRGM)</collab>
<source><![CDATA[Colloque sur le Crétacé Inférieur, 1965, Mémoire, Lyon, septembre 1963)]]></source>
<year>1965</year>
<page-range>840</page-range><publisher-loc><![CDATA[Paris ]]></publisher-loc>
<publisher-name><![CDATA[Editions B.R.G.M (Bureau de Recherches Géologiques et Minieres)]]></publisher-name>
</nlm-citation>
</ref>
<ref id="B11">
<nlm-citation citation-type="journal">
<person-group person-group-type="author">
<name>
<surname><![CDATA[Busnardo]]></surname>
<given-names><![CDATA[R.]]></given-names>
</name>
</person-group>
<article-title xml:lang=""><![CDATA[Ammonites in Synthése Géologique du Sud-Est de la France, Chapitre Crétacé inférieur]]></article-title>
<source><![CDATA[Orléans, Bureau de Recherches Géologiques et Minieres, Mémoir]]></source>
<year>1984</year>
<volume>125</volume>
<page-range>292-4</page-range></nlm-citation>
</ref>
<ref id="B12">
<nlm-citation citation-type="">
<person-group person-group-type="author">
<name>
<surname><![CDATA[Cantú-Chapa]]></surname>
<given-names><![CDATA[A.]]></given-names>
</name>
</person-group>
<source><![CDATA[Étude Biostratigraphique des Ammonites du Centre et de l&#8217;est du Mexique (Jurassique supérieur et Crétacé)]]></source>
<year>1963</year>
<page-range>102</page-range></nlm-citation>
</ref>
<ref id="B13">
<nlm-citation citation-type="journal">
<person-group person-group-type="author">
<name>
<surname><![CDATA[Cantú-Chapa]]></surname>
<given-names><![CDATA[C.M]]></given-names>
</name>
</person-group>
<article-title xml:lang=""><![CDATA[Estratigrafía de la Formación La Peña (Aptiano Superior) en el área de Monterrey, N. L.]]></article-title>
<source><![CDATA[Revista del Instituto Mexicano del Petróleo]]></source>
<year>1976</year>
<volume>8</volume>
<numero>4</numero>
<issue>4</issue>
<page-range>7-16</page-range></nlm-citation>
</ref>
<ref id="B14">
<nlm-citation citation-type="journal">
<person-group person-group-type="author">
<name>
<surname><![CDATA[Casey]]></surname>
<given-names><![CDATA[R.]]></given-names>
</name>
</person-group>
<article-title xml:lang=""><![CDATA[The stratigraphical paleontology of the Lower Greensand]]></article-title>
<source><![CDATA[Paleontology]]></source>
<year>1961</year>
<volume>3</volume>
<page-range>487-621</page-range></nlm-citation>
</ref>
<ref id="B15">
<nlm-citation citation-type="journal">
<person-group person-group-type="author">
<name>
<surname><![CDATA[Contreras-Montero]]></surname>
<given-names><![CDATA[B.]]></given-names>
</name>
</person-group>
<article-title xml:lang=""><![CDATA[Bioestratigrafía de las Formaciones Taraises y La Peña (Cretácico Inferior) de La Goleta, Coahuila y Minillas, Nuevo León]]></article-title>
<source><![CDATA[Revista del Instituto Mexicano del Petróleo]]></source>
<year>1977</year>
<volume>9</volume>
<numero>1</numero>
<issue>1</issue>
<page-range>8-17</page-range></nlm-citation>
</ref>
<ref id="B16">
<nlm-citation citation-type="journal">
<person-group person-group-type="author">
<name>
<surname><![CDATA[Delanoy]]></surname>
<given-names><![CDATA[G.]]></given-names>
</name>
</person-group>
<article-title xml:lang=""><![CDATA[About some significant ammonites from the Lower Aptian (Bedoulian) of the Angles-Barrême area (South-East France)]]></article-title>
<person-group person-group-type="editor">
<name>
<surname><![CDATA[Cecca]]></surname>
<given-names><![CDATA[F.]]></given-names>
</name>
</person-group>
<source><![CDATA[Memorie descrittive della carta geologica d&#8217;Italia]]></source>
<year>1995</year>
<page-range>65-101</page-range></nlm-citation>
</ref>
<ref id="B17">
<nlm-citation citation-type="journal">
<person-group person-group-type="author">
<name>
<surname><![CDATA[d&#8217;Orbigny]]></surname>
<given-names><![CDATA[A.]]></given-names>
</name>
</person-group>
<article-title xml:lang=""><![CDATA[Paléontologie Française. Terraines Crétacés. I]]></article-title>
<source><![CDATA[Cephalopodes]]></source>
<year>1842</year>
<page-range>662</page-range><publisher-loc><![CDATA[Paris ]]></publisher-loc>
</nlm-citation>
</ref>
<ref id="B18">
<nlm-citation citation-type="journal">
<person-group person-group-type="author">
<name>
<surname><![CDATA[Erba]]></surname>
<given-names><![CDATA[E.]]></given-names>
</name>
</person-group>
<article-title xml:lang=""><![CDATA[The Aptian Stage]]></article-title>
<source><![CDATA[Bulletin de l´Institute Royal des Sciences Naturelles de Belgique, Sciences de la Terre]]></source>
<year>1996</year>
<volume>66</volume>
<page-range>31-43</page-range></nlm-citation>
</ref>
<ref id="B19">
<nlm-citation citation-type="journal">
<person-group person-group-type="author">
<name>
<surname><![CDATA[Hill]]></surname>
<given-names><![CDATA[R.T.]]></given-names>
</name>
</person-group>
<article-title xml:lang=""><![CDATA[Paleontology of the Cretaceous formations of Texas]]></article-title>
<source><![CDATA[Proceedings of the Biological Society of Washington]]></source>
<year>1893</year>
<volume>8</volume>
<page-range>9-40</page-range></nlm-citation>
</ref>
<ref id="B20">
<nlm-citation citation-type="journal">
<person-group person-group-type="author">
<name>
<surname><![CDATA[Hoedemaeker]]></surname>
<given-names><![CDATA[Ph.J.]]></given-names>
</name>
<name>
<surname><![CDATA[Bulot]]></surname>
<given-names><![CDATA[L.]]></given-names>
</name>
</person-group>
<article-title xml:lang=""><![CDATA[Preliminary ammonite zonation for the Lower Cretaceous of the Mediterranean Region]]></article-title>
<source><![CDATA[Géologie Alpine]]></source>
<year>1990</year>
<volume>66</volume>
<page-range>123-7</page-range></nlm-citation>
</ref>
<ref id="B21">
<nlm-citation citation-type="journal">
<person-group person-group-type="author">
<name>
<surname><![CDATA[Hoedemaeker]]></surname>
<given-names><![CDATA[Ph.J.]]></given-names>
</name>
<name>
<surname><![CDATA[Rawson]]></surname>
<given-names><![CDATA[P.F.]]></given-names>
</name>
</person-group>
<article-title xml:lang=""><![CDATA[Report on the 5th International Workshop of the Lower Cretaceous Cephalopod Team, Vienna, September 5, 2000]]></article-title>
<source><![CDATA[Cretaceous Research]]></source>
<year>2000</year>
<volume>21</volume>
<page-range>857-60</page-range></nlm-citation>
</ref>
<ref id="B22">
<nlm-citation citation-type="journal">
<person-group person-group-type="author">
<name>
<surname><![CDATA[Hoedemaeker]]></surname>
<given-names><![CDATA[Ph.J.]]></given-names>
</name>
<name>
<surname><![CDATA[Company]]></surname>
<given-names><![CDATA[M.]]></given-names>
</name>
<name>
<surname><![CDATA[Aguirre-Urreta]]></surname>
<given-names><![CDATA[M.B.]]></given-names>
</name>
<name>
<surname><![CDATA[Avram]]></surname>
<given-names><![CDATA[E.]]></given-names>
</name>
<name>
<surname><![CDATA[Bogdanova]]></surname>
<given-names><![CDATA[T.N.]]></given-names>
</name>
<name>
<surname><![CDATA[Bujtor]]></surname>
<given-names><![CDATA[L.]]></given-names>
</name>
<name>
<surname><![CDATA[Bulot]]></surname>
<given-names><![CDATA[L.]]></given-names>
</name>
<name>
<surname><![CDATA[Cecca]]></surname>
<given-names><![CDATA[F.]]></given-names>
</name>
<name>
<surname><![CDATA[Delanoy]]></surname>
<given-names><![CDATA[G.]]></given-names>
</name>
<name>
<surname><![CDATA[Ettachffini]]></surname>
<given-names><![CDATA[M.]]></given-names>
</name>
<name>
<surname><![CDATA[Memmi]]></surname>
<given-names><![CDATA[L.]]></given-names>
</name>
<name>
<surname><![CDATA[Owen]]></surname>
<given-names><![CDATA[H. G.]]></given-names>
</name>
<name>
<surname><![CDATA[Rawson]]></surname>
<given-names><![CDATA[P.F.]]></given-names>
</name>
<name>
<surname><![CDATA[Sandoval]]></surname>
<given-names><![CDATA[J.]]></given-names>
</name>
<name>
<surname><![CDATA[Tavera]]></surname>
<given-names><![CDATA[J.M.]]></given-names>
</name>
<name>
<surname><![CDATA[Thieuloy]]></surname>
<given-names><![CDATA[J.-P.]]></given-names>
</name>
<name>
<surname><![CDATA[Tovbina]]></surname>
<given-names><![CDATA[S.Z.]]></given-names>
</name>
<name>
<surname><![CDATA[Va&#353;í&#269;ek]]></surname>
<given-names><![CDATA[Z.]]></given-names>
</name>
</person-group>
<article-title xml:lang=""><![CDATA[Ammonite zonation for the Lower Cretaceous of the Mediterranean region; basis for the stratigraphic correlations within IGCP-Project 262]]></article-title>
<source><![CDATA[Revista Española de Paleontología]]></source>
<year>1993</year>
<volume>8</volume>
<page-range>117-20</page-range></nlm-citation>
</ref>
<ref id="B23">
<nlm-citation citation-type="journal">
<person-group person-group-type="author">
<name>
<surname><![CDATA[Hoedemaeker]]></surname>
<given-names><![CDATA[Ph.J.]]></given-names>
</name>
<name>
<surname><![CDATA[Reboulet]]></surname>
<given-names><![CDATA[S.]]></given-names>
</name>
<name>
<surname><![CDATA[Aguirre-Urreta]]></surname>
<given-names><![CDATA[M.B.]]></given-names>
</name>
<name>
<surname><![CDATA[Alsen]]></surname>
<given-names><![CDATA[P.]]></given-names>
</name>
<name>
<surname><![CDATA[Aoutem]]></surname>
<given-names><![CDATA[M.]]></given-names>
</name>
<name>
<surname><![CDATA[Atrops]]></surname>
<given-names><![CDATA[F.]]></given-names>
</name>
<name>
<surname><![CDATA[Barragan]]></surname>
<given-names><![CDATA[R.]]></given-names>
</name>
<name>
<surname><![CDATA[Company]]></surname>
<given-names><![CDATA[M.]]></given-names>
</name>
<name>
<surname><![CDATA[González-Arreola]]></surname>
<given-names><![CDATA[C.]]></given-names>
</name>
<name>
<surname><![CDATA[Klein]]></surname>
<given-names><![CDATA[J.]]></given-names>
</name>
<name>
<surname><![CDATA[Lukeneder]]></surname>
<given-names><![CDATA[A.]]></given-names>
</name>
<name>
<surname><![CDATA[Ploch]]></surname>
<given-names><![CDATA[I.]]></given-names>
</name>
<name>
<surname><![CDATA[Raisossadat]]></surname>
<given-names><![CDATA[N.]]></given-names>
</name>
<name>
<surname><![CDATA[Rawson]]></surname>
<given-names><![CDATA[P.F.]]></given-names>
</name>
<name>
<surname><![CDATA[Ropolo]]></surname>
<given-names><![CDATA[P.]]></given-names>
</name>
<name>
<surname><![CDATA[Va&#353;í&#269;ek]]></surname>
<given-names><![CDATA[Z.]]></given-names>
</name>
<name>
<surname><![CDATA[Vermeulen]]></surname>
<given-names><![CDATA[J.]]></given-names>
</name>
<name>
<surname><![CDATA[Wippich]]></surname>
<given-names><![CDATA[M.]]></given-names>
</name>
</person-group>
<article-title xml:lang=""><![CDATA[Report on the 1st International Workshop of the IUGS Lower Cretaceous Ammonite Working Group, the &#8216;Kilian Group&#8217;, Lyon, July 11, 2002)]]></article-title>
<source><![CDATA[Cretaceous Research]]></source>
<year>2003</year>
<volume>24</volume>
<page-range>89-94</page-range></nlm-citation>
</ref>
<ref id="B24">
<nlm-citation citation-type="journal">
<person-group person-group-type="author">
<name>
<surname><![CDATA[Humphrey]]></surname>
<given-names><![CDATA[W.E.]]></given-names>
</name>
</person-group>
<article-title xml:lang=""><![CDATA[Geology of Sierra de Los Muertos area, Mexico (with descriptions of Aptian cephalopods from the La Peña Formation)]]></article-title>
<source><![CDATA[Geological Society of America Bulletin]]></source>
<year>1949</year>
<volume>60</volume>
<page-range>89-176</page-range></nlm-citation>
</ref>
<ref id="B25">
<nlm-citation citation-type="journal">
<person-group person-group-type="author">
<name>
<surname><![CDATA[Imlay]]></surname>
<given-names><![CDATA[R.W.]]></given-names>
</name>
</person-group>
<article-title xml:lang=""><![CDATA[Evolution of the Coahuila Peninsula, Mexico, Part IV. Geology of the western part of the Sierra de Parras]]></article-title>
<source><![CDATA[Geological Society of America Bulletin]]></source>
<year>1936</year>
<volume>47</volume>
<page-range>1091-152</page-range></nlm-citation>
</ref>
<ref id="B26">
<nlm-citation citation-type="book">
<person-group person-group-type="author">
<name>
<surname><![CDATA[Kilian]]></surname>
<given-names><![CDATA[W.]]></given-names>
</name>
</person-group>
<source><![CDATA[Description Géologique de la Montagne de Lure (Basses-Alpes)]]></source>
<year>1888</year>
<page-range>458</page-range><publisher-loc><![CDATA[Paris ]]></publisher-loc>
<publisher-name><![CDATA[Université Masson]]></publisher-name>
</nlm-citation>
</ref>
<ref id="B27">
<nlm-citation citation-type="book">
<person-group person-group-type="author">
<name>
<surname><![CDATA[Méndez-Franco]]></surname>
<given-names><![CDATA[A.L.]]></given-names>
</name>
</person-group>
<source><![CDATA[Bioestratigrafía de ammonites y variaciones de litofacies en una secuencia estratigráfica del Berremiano-Aptiano (Cretácico Inferior) del área del Cañón de La Huasteca, Estado de Nuevo León]]></source>
<year>2003</year>
<page-range>179</page-range><publisher-loc><![CDATA[México, D. F. ]]></publisher-loc>
<publisher-name><![CDATA[Universidad Nacional Autónoma de México, Facultad de Ciencias]]></publisher-name>
</nlm-citation>
</ref>
<ref id="B28">
<nlm-citation citation-type="journal">
<person-group person-group-type="author">
<name>
<surname><![CDATA[Morán-Zenteno]]></surname>
<given-names><![CDATA[D.]]></given-names>
</name>
</person-group>
<article-title xml:lang=""><![CDATA[Geology of the Mexican Republic]]></article-title>
<source><![CDATA[American Association of Petroleum Geologists, Studies in Geology]]></source>
<year>1994</year>
<volume>39</volume>
<page-range>160</page-range></nlm-citation>
</ref>
<ref id="B29">
<nlm-citation citation-type="book">
<person-group person-group-type="author">
<name>
<surname><![CDATA[Muir]]></surname>
<given-names><![CDATA[J.M.]]></given-names>
</name>
</person-group>
<source><![CDATA[Geology of the Tampico Region, Mexico]]></source>
<year>1936</year>
<page-range>200</page-range><publisher-name><![CDATA[American Association of Petroleum Geologists]]></publisher-name>
</nlm-citation>
</ref>
<ref id="B30">
<nlm-citation citation-type="journal">
<collab>North American Commission on Stratigraphy Nomenclature</collab>
<article-title xml:lang=""><![CDATA[North American Stratigraphic Code]]></article-title>
<source><![CDATA[American Association of Petroleum Geologists Bulletin]]></source>
<year>1983</year>
<volume>67</volume>
<page-range>841-75</page-range></nlm-citation>
</ref>
<ref id="B31">
<nlm-citation citation-type="journal">
<person-group person-group-type="author">
<name>
<surname><![CDATA[Rawson]]></surname>
<given-names><![CDATA[P.]]></given-names>
</name>
</person-group>
<article-title xml:lang=""><![CDATA[The Valanginian to Aptian stages; Current definitions and outstanding problems]]></article-title>
<source><![CDATA[Zitteliana]]></source>
<year>1983</year>
<volume>10</volume>
<page-range>493-500</page-range></nlm-citation>
</ref>
<ref id="B32">
<nlm-citation citation-type="journal">
<person-group person-group-type="author">
<name>
<surname><![CDATA[Scott]]></surname>
<given-names><![CDATA[G.]]></given-names>
</name>
</person-group>
<article-title xml:lang=""><![CDATA[Cephalopods from the Cretaceous Trinity Group of the south-central United States]]></article-title>
<source><![CDATA[University of Texas, Publication]]></source>
<year>1940</year>
<volume>3945</volume>
<page-range>969-1106</page-range></nlm-citation>
</ref>
<ref id="B33">
<nlm-citation citation-type="">
<person-group person-group-type="author">
<name>
<surname><![CDATA[Spath]]></surname>
<given-names><![CDATA[L.F.]]></given-names>
</name>
</person-group>
<source><![CDATA[Ammonoidea of the Gault]]></source>
<year>1943</year>
<page-range>787</page-range></nlm-citation>
</ref>
<ref id="B34">
<nlm-citation citation-type="journal">
<person-group person-group-type="author">
<name>
<surname><![CDATA[Stoyanow]]></surname>
<given-names><![CDATA[A.]]></given-names>
</name>
</person-group>
<article-title xml:lang=""><![CDATA[Lower Cretaceous Stratigraphy in Southeastern Arizona]]></article-title>
<source><![CDATA[Geological Society of America, Memoir]]></source>
<year>1949</year>
<volume>38</volume>
<page-range>169</page-range></nlm-citation>
</ref>
<ref id="B35">
<nlm-citation citation-type="journal">
<person-group person-group-type="author">
<name>
<surname><![CDATA[Szives]]></surname>
<given-names><![CDATA[O.]]></given-names>
</name>
</person-group>
<article-title xml:lang=""><![CDATA[Ammonite biostratigraphy of the Tata Limestone Formation (Aptian -Lower Albian), Hungary]]></article-title>
<source><![CDATA[Acta Geologica Hungarica]]></source>
<year>1999</year>
<volume>42</volume>
<page-range>401-11</page-range></nlm-citation>
</ref>
<ref id="B36">
<nlm-citation citation-type="journal">
<person-group person-group-type="author">
<name>
<surname><![CDATA[Toucas]]></surname>
<given-names><![CDATA[A.]]></given-names>
</name>
</person-group>
<article-title xml:lang=""><![CDATA[Note sur le Jurassique supérieur et le Crétacé inférieur de la vallée du Rhône]]></article-title>
<source><![CDATA[Bulletin Société Géologique de France]]></source>
<year>1888</year>
<volume>16</volume>
<numero>3</numero>
<issue>3</issue>
<page-range>903</page-range></nlm-citation>
</ref>
<ref id="B37">
<nlm-citation citation-type="journal">
<person-group person-group-type="author">
<name>
<surname><![CDATA[Young]]></surname>
<given-names><![CDATA[K.]]></given-names>
</name>
</person-group>
<article-title xml:lang=""><![CDATA[Ammonite zones of northern Chihuahua]]></article-title>
<person-group person-group-type="editor">
<name>
<surname><![CDATA[Cordoba]]></surname>
<given-names><![CDATA[D.A.]]></given-names>
</name>
<name>
<surname><![CDATA[Wengerd]]></surname>
<given-names><![CDATA[S.A.]]></given-names>
</name>
<name>
<surname><![CDATA[Shomaker]]></surname>
<given-names><![CDATA[J.]]></given-names>
</name>
</person-group>
<source><![CDATA[New Mexico Geological Society, Guidebook]]></source>
<year>1969</year>
<page-range>97-101</page-range></nlm-citation>
</ref>
</ref-list>
</back>
</article>
