diff --git a/public/java/src/org/broadinstitute/sting/commandline/ArgumentTypeDescriptor.java b/public/java/src/org/broadinstitute/sting/commandline/ArgumentTypeDescriptor.java
index 622576747..d341b2cde 100644
--- a/public/java/src/org/broadinstitute/sting/commandline/ArgumentTypeDescriptor.java
+++ b/public/java/src/org/broadinstitute/sting/commandline/ArgumentTypeDescriptor.java
@@ -27,6 +27,7 @@ package org.broadinstitute.sting.commandline;
 
 import org.apache.log4j.Logger;
 import org.broad.tribble.Feature;
+import org.broadinstitute.sting.gatk.refdata.tracks.FeatureManager;
 import org.broadinstitute.sting.gatk.walkers.Multiplex;
 import org.broadinstitute.sting.gatk.walkers.Multiplexer;
 import org.broadinstitute.sting.utils.classloader.JVMUtils;
@@ -313,19 +314,42 @@ class RodBindingArgumentTypeDescriptor extends ArgumentTypeDescriptor {
         String value = getArgumentValue( defaultDefinition, matches );
         try {
             String name = defaultDefinition.fullName;
-            String tribbleType;
+            String tribbleType = null;
             Tags tags = getArgumentTags(matches);
             // must have one or two tag values here
             if ( tags.getPositionalTags().size() == 2 ) { // -X:name,type style
                 name = tags.getPositionalTags().get(0);
                 tribbleType = tags.getPositionalTags().get(1);
-            } else if ( tags.getPositionalTags().size() == 1 ) { // -X:type style
-                tribbleType = tags.getPositionalTags().get(0);
-            } else
-                throw new UserException.CommandLineException(
-                        String.format("Unexpected number of positional tags for argument %s : %s. " +
-                                "Rod bindings only suport -X:type and -X:name,type argument styles",
-                                value, source.field.getName()));
+            } else {
+                if ( tags.getPositionalTags().size() == 1 ) {
+                    // -X:type style is a type when we cannot determine the type dynamically
+                    tribbleType = tags.getPositionalTags().get(0);
+                }
+
+                // try to determine the file type dynamically
+                FeatureManager manager = new FeatureManager();
+                File file = new File(value);
+                if ( file.canRead() && file.isFile() ) {
+                    FeatureManager.FeatureDescriptor featureDescriptor = manager.getByFiletype(file);
+                    if ( featureDescriptor != null ) {
+                        tribbleType = featureDescriptor.getName();
+                        logger.warn("Dynamically determined of " + file + " to be " + tribbleType);
+
+                        if ( tags.getPositionalTags().size() == 1 ) {
+                            // -X:type style is a name when we can determine the type dynamically
+                            name = tags.getPositionalTags().get(0);
+                        }
+                    }
+                }
+
+                // now, if we haven't found a type
+                if ( tribbleType == null )
+                    throw new UserException.CommandLineException(
+                            String.format("Unexpected number of positional tags for argument %s : %s. " +
+                                    "Rod bindings only suport -X:type and -X:name,type argument styles",
+                                    value, source.field.getName()));
+            }
+
             Constructor ctor = (makeRawTypeIfNecessary(type)).getConstructor(Class.class, String.class, String.class, String.class, Tags.class);
             Class parameterType = getParameterizedTypeClass(type);
             RodBinding result = (RodBinding)ctor.newInstance(parameterType, name, value, tribbleType, tags);
diff --git a/public/java/test/org/broadinstitute/sting/commandline/ParsingEngineUnitTest.java b/public/java/test/org/broadinstitute/sting/commandline/ParsingEngineUnitTest.java
index 63e1a59bd..366401ad6 100755
--- a/public/java/test/org/broadinstitute/sting/commandline/ParsingEngineUnitTest.java
+++ b/public/java/test/org/broadinstitute/sting/commandline/ParsingEngineUnitTest.java
@@ -26,6 +26,7 @@
 package org.broadinstitute.sting.commandline;
 
 import org.broad.tribble.Feature;
+import org.broadinstitute.sting.gatk.refdata.features.beagle.BeagleFeature;
 import org.broadinstitute.sting.utils.exceptions.UserException;
 import org.broadinstitute.sting.utils.variantcontext.VariantContext;
 import org.testng.Assert;
@@ -837,5 +838,87 @@ public class ParsingEngineUnitTest extends BaseTest {
         Assert.assertEquals(argProvider.bindings.get(1).getName(), "foo2", "Name isn't set properly");
     }
 
+    private final static String HISEQ_VCF = testDir + "HiSeq.10000.vcf";
+    private final static String TRANCHES_FILE = testDir + "tranches.6.txt";
 
+    @Test
+    public void variantContextBindingTestDynamicTyping1() {
+        final String[] commandLine = new String[] {"-V", HISEQ_VCF};
+
+        parsingEngine.addArgumentSource( VariantContextRodBindingArgProvider.class );
+        parsingEngine.parse( commandLine );
+        parsingEngine.validate();
+
+        VariantContextRodBindingArgProvider argProvider = new VariantContextRodBindingArgProvider();
+        parsingEngine.loadArgumentsIntoObject( argProvider );
+
+        Assert.assertEquals(argProvider.binding.getName(), "binding", "Name isn't set properly");
+        Assert.assertEquals(argProvider.binding.getSource(), HISEQ_VCF, "Source isn't set to its expected value");
+        Assert.assertEquals(argProvider.binding.getType(), VariantContext.class, "Type isn't set to its expected value");
+        Assert.assertEquals(argProvider.binding.getTags().getPositionalTags().size(), 0, "Tags aren't correctly set");
+    }
+
+    @Test
+    public void variantContextBindingTestDynamicTypingNameAsSingleArgument() {
+        final String[] commandLine = new String[] {"-V:name", HISEQ_VCF};
+
+        parsingEngine.addArgumentSource( VariantContextRodBindingArgProvider.class );
+        parsingEngine.parse( commandLine );
+        parsingEngine.validate();
+
+        VariantContextRodBindingArgProvider argProvider = new VariantContextRodBindingArgProvider();
+        parsingEngine.loadArgumentsIntoObject( argProvider );
+
+        Assert.assertEquals(argProvider.binding.getName(), "name", "Name isn't set properly");
+        Assert.assertEquals(argProvider.binding.getSource(), HISEQ_VCF, "Source isn't set to its expected value");
+        Assert.assertEquals(argProvider.binding.getType(), VariantContext.class, "Type isn't set to its expected value");
+        Assert.assertEquals(argProvider.binding.getTags().getPositionalTags().size(), 1, "Tags aren't correctly set");
+    }
+
+    @Test()
+    public void variantContextBindingTestDynamicTypingTwoTagsPassing() {
+        final String[] commandLine = new String[] {"-V:name,vcf", HISEQ_VCF};
+
+        parsingEngine.addArgumentSource( VariantContextRodBindingArgProvider.class );
+        parsingEngine.parse( commandLine );
+        parsingEngine.validate();
+
+        VariantContextRodBindingArgProvider argProvider = new VariantContextRodBindingArgProvider();
+        parsingEngine.loadArgumentsIntoObject( argProvider );
+
+        Assert.assertEquals(argProvider.binding.getName(), "name", "Name isn't set properly");
+        Assert.assertEquals(argProvider.binding.getSource(), HISEQ_VCF, "Source isn't set to its expected value");
+        Assert.assertEquals(argProvider.binding.getType(), VariantContext.class, "Type isn't set to its expected value");
+        Assert.assertEquals(argProvider.binding.getTags().getPositionalTags().size(), 2, "Tags aren't correctly set");
+    }
+
+    @Test()
+    public void variantContextBindingTestDynamicTypingTwoTagsCausingTypeFailure() {
+        final String[] commandLine = new String[] {"-V:name,beagle", HISEQ_VCF};
+
+        parsingEngine.addArgumentSource( VariantContextRodBindingArgProvider.class );
+        parsingEngine.parse( commandLine );
+        parsingEngine.validate();
+
+        VariantContextRodBindingArgProvider argProvider = new VariantContextRodBindingArgProvider();
+        parsingEngine.loadArgumentsIntoObject(argProvider);
+
+        Assert.assertEquals(argProvider.binding.getName(), "name", "Name isn't set properly");
+        Assert.assertEquals(argProvider.binding.getSource(), HISEQ_VCF, "Source isn't set to its expected value");
+        Assert.assertEquals(argProvider.binding.getType(), VariantContext.class, "Type isn't set to its expected value");
+        Assert.assertEquals(argProvider.binding.getTribbleType(), "beagle", "Type isn't set to its expected value");
+        Assert.assertEquals(argProvider.binding.getTags().getPositionalTags().size(), 2, "Tags aren't correctly set");
+    }
+
+    @Test(expectedExceptions = UserException.class)
+    public void variantContextBindingTestDynamicTypingUnknownTribbleType() {
+        final String[] commandLine = new String[] {"-V", TRANCHES_FILE};
+
+        parsingEngine.addArgumentSource( VariantContextRodBindingArgProvider.class );
+        parsingEngine.parse( commandLine );
+        parsingEngine.validate();
+
+        VariantContextRodBindingArgProvider argProvider = new VariantContextRodBindingArgProvider();
+        parsingEngine.loadArgumentsIntoObject( argProvider );
+    }
 }