When enabling additional logging to system DEBUG on startup of standalone-full.xml it is possible to see:

07:15:40,780 DEBUG [org.jboss.tm.TransactionManagerLocator] (MSC service thread 1-2) Unable to lookup: java:/TransactionManager: javax.naming.NameNotFoundException: Error looking up TransactionManager, service service jboss.naming.context.java.TransactionManager is not started
at org.jboss.as.naming.ServiceBasedNamingStore.lookup(ServiceBasedNamingStore.java:132) [jboss-as-naming-7.2.0.Alpha1-redhat-4.jar:7.2.0.Alpha1-redhat-4]
at org.jboss.as.naming.ServiceBasedNamingStore.lookup(ServiceBasedNamingStore.java:80) [jboss-as-naming-7.2.0.Alpha1-redhat-4.jar:7.2.0.Alpha1-redhat-4]
at org.jboss.as.naming.NamingContext.lookup(NamingContext.java:197) [jboss-as-naming-7.2.0.Alpha1-redhat-4.jar:7.2.0.Alpha1-redhat-4]
at org.jboss.as.naming.InitialContext.lookup(InitialContext.java:120) [jboss-as-naming-7.2.0.Alpha1-redhat-4.jar:7.2.0.Alpha1-redhat-4]
at org.jboss.as.naming.NamingContext.lookup(NamingContext.java:183) [jboss-as-naming-7.2.0.Alpha1-redhat-4.jar:7.2.0.Alpha1-redhat-4]
at org.jboss.as.naming.NamingContext.lookup(NamingContext.java:179) [jboss-as-naming-7.2.0.Alpha1-redhat-4.jar:7.2.0.Alpha1-redhat-4]
at javax.naming.InitialContext.lookup(InitialContext.java:411) [rt.jar:1.7.0_17]
at org.jboss.tm.TransactionManagerLocator.tryJNDI(TransactionManagerLocator.java:150) [jboss-transaction-spi-7.0.0.Final.jar:7.0.0.Final]
at org.jboss.tm.TransactionManagerLocator.locate(TransactionManagerLocator.java:131) [jboss-transaction-spi-7.0.0.Final.jar:7.0.0.Final]
at org.jboss.tm.TransactionManagerLocator.locateTransactionManager(TransactionManagerLocator.java:94) [jboss-transaction-spi-7.0.0.Final.jar:7.0.0.Final]
at org.jboss.tm.usertx.client.ServerVMClientUserTransaction.<init>(ServerVMClientUserTransaction.java:93) [jboss-transaction-spi-7.0.0.Final.jar:7.0.0.Final]
at org.jboss.tm.usertx.client.ServerVMClientUserTransaction.<clinit>(ServerVMClientUserTransaction.java:60) [jboss-transaction-spi-7.0.0.Final.jar:7.0.0.Final]
at org.jboss.as.txn.service.ArjunaTransactionManagerService.start(ArjunaTransactionManagerService.java:115) [jboss-as-transactions-7.2.0.Alpha1-redhat-4.jar:7.2.0.Alpha1-redhat-4]
at org.jboss.msc.service.ServiceControllerImpl$StartTask.startService(ServiceControllerImpl.java:1811) [jboss-msc-1.0.4.GA.jar:1.0.4.GA]
at org.jboss.msc.service.ServiceControllerImpl$StartTask.run(ServiceControllerImpl.java:1746) [jboss-msc-1.0.4.GA.jar:1.0.4.GA]
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1145) [rt.jar:1.7.0_17]
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615) [rt.jar:1.7.0_17]
at java.lang.Thread.run(Thread.java:722) [rt.jar:1.7.0_17]

07:15:40,786 DEBUG [org.jboss.tm.TransactionManagerLocator] (MSC service thread 1-2) Unable to instantiate legacy transaction manager: java.lang.ClassNotFoundException: org.jboss.tm.TxManager from [Module "org.jboss.jboss-transaction-spi:main" from local module loader @634f6b14 (finder: local module finder @72ff20fb (roots: F:\Devel\deps\jboss-eap-6.1\modules,F:\Devel\deps\jboss-eap-6.1\modules\system\layers\base))]
at org.jboss.modules.ModuleClassLoader.findClass(ModuleClassLoader.java:190) [jboss-modules.jar:1.2.0.CR1]
at org.jboss.modules.ConcurrentClassLoader.performLoadClassUnchecked(ConcurrentClassLoader.java:468) [jboss-modules.jar:1.2.0.CR1]
at org.jboss.modules.ConcurrentClassLoader.performLoadClassChecked(ConcurrentClassLoader.java:456) [jboss-modules.jar:1.2.0.CR1]
at org.jboss.modules.ConcurrentClassLoader.performLoadClass(ConcurrentClassLoader.java:398) [jboss-modules.jar:1.2.0.CR1]
at org.jboss.modules.ConcurrentClassLoader.loadClass(ConcurrentClassLoader.java:120) [jboss-modules.jar:1.2.0.CR1]
at java.lang.Class.forName0(Native Method) [rt.jar:1.7.0_17]
at java.lang.Class.forName(Class.java:188) [rt.jar:1.7.0_17]
at org.jboss.tm.TransactionManagerLocator.usePrivateAPI(TransactionManagerLocator.java:172) [jboss-transaction-spi-7.0.0.Final.jar:7.0.0.Final]
at org.jboss.tm.TransactionManagerLocator.locate(TransactionManagerLocator.java:133) [jboss-transaction-spi-7.0.0.Final.jar:7.0.0.Final]
at org.jboss.tm.TransactionManagerLocator.locateTransactionManager(TransactionManagerLocator.java:94) [jboss-transaction-spi-7.0.0.Final.jar:7.0.0.Final]
at org.jboss.tm.usertx.client.ServerVMClientUserTransaction.<init>(ServerVMClientUserTransaction.java:93) [jboss-transaction-spi-7.0.0.Final.jar:7.0.0.Final]
at org.jboss.tm.usertx.client.ServerVMClientUserTransaction.<clinit>(ServerVMClientUserTransaction.java:60) [jboss-transaction-spi-7.0.0.Final.jar:7.0.0.Final]
at org.jboss.as.txn.service.ArjunaTransactionManagerService.start(ArjunaTransactionManagerService.java:115) [jboss-as-transactions-7.2.0.Alpha1-redhat-4.jar:7.2.0.Alpha1-redhat-4]
at org.jboss.msc.service.ServiceControllerImpl$StartTask.startService(ServiceControllerImpl.java:1811) [jboss-msc-1.0.4.GA.jar:1.0.4.GA]
at org.jboss.msc.service.ServiceControllerImpl$StartTask.run(ServiceControllerImpl.java:1746) [jboss-msc-1.0.4.GA.jar:1.0.4.GA]
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1145) [rt.jar:1.7.0_17]
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615) [rt.jar:1.7.0_17]
at java.lang.Thread.run(Thread.java:722) [rt.jar:1.7.0_17]