No Persistence provider for EntityManager named default

<persistence-unit name="default"  transaction-type="JTA">
	    <provider>org.hibernate.ejb.HibernatePersistence</provider>
		<jta-data-source>java:jboss/datasources/testeDatasource</jta-data-source>
		<properties>
		    <property name="hibernate.dialect" value="org.hibernate.dialect.Oracle10gDialect"/>
		    <property name="hibernate.check-valid-connection-sql" value="select 0 from dual"/>
		</properties>
	    </persistence-unit>

protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
		EntityManager em = Persistence.createEntityManagerFactory("default").createEntityManager();
		TypedQuery<Pessoa> query = em.createQuery("select p from Pessoa p",Pessoa.class);
		List<Pessoa> pessoas = query.getResultList();
		for (Pessoa p : pessoas){
			System.out.println(p.getNome());
		}
	}

protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
		EntityManager em = Persistence.createEntityManagerFactory("ConexaoJPA").createEntityManager();
		TypedQuery<Pessoa> query = em.createQuery("select p from Pessoa p",Pessoa.class);
		List<Pessoa> pessoas = query.getResultList();
		for (Pessoa p : pessoas){
			System.out.println(p.getNome());
		}
	}

<datasources>
<datasource jndi-name="java:/MeudatasourceDS" pool-name="DatasourceUC" enabled="true" jta="true" use-java-context="true" use-ccm="true">
    <connection-url>jdbc:oracle:thin:@localhost:1521/xe</connection-url>
    <driver>oracle</driver>
    <transaction-isolation>TRANSACTION_READ_COMMITTED</transaction-isolation>
    <pool>
	<min-pool-size>0</min-pool-size>
	<max-pool-size>20</max-pool-size>
	<prefill>true</prefill>
	<use-strict-min>false</use-strict-min>
	<flush-strategy>FailingConnectionOnly</flush-strategy>
    </pool>
    <security><user-name>teste</user-name>
	<password>teste</password>
    </security>
</datasource>
<drivers>
    <driver name="oracle" module="com.oracle.ojdbc6">
	<xa-datasource-class>oracle.jdbc.OracleDriver</xa-datasource-class>
    </driver>
</drivers>
</datasources>

public static Connection getConexao() {
		DataSource ds = null;
		Connection con = null;
		InitialContext ic;
		try {
			ic = new InitialContext();
			ds = (DataSource) ic.lookup("java:/MeudatasourceDS");
			con = ds.getConnection();
		} catch (Exception e) {
			System.out.println("Erro a pegar conexao: " + e.getMessage());
			e.printStackTrace();
		}
		return con;
	}

<?xml version="1.0" encoding="UTF-8"?>

<datasources>
	<local-tx-datasource>
		<jndi-name>MeuDataSourceDS</jndi-name>
		<connection-url>jdbc:postgresql://localhost:5432/nomadscity</connection-url>
		<driver-class>org.postgresql.Driver</driver-class>
		<user-name>postgres</user-name>
		<password>postgres</password>
		<!-- sql to call when connection is created. Can be anything, select 1 is valid for PostgreSQL <new-connection-sql>select 1</new-connection-sql> -->

		<!-- sql to call on an existing pooled connection when it is obtained from pool. Can be anything, select 1 is valid for PostgreSQL <check-valid-connection-sql>select
			1</check-valid-connection-sql> -->

		<!-- corresponding type-mapping in the standardjbosscmp-jdbc.xml (optional) -->
		<metadata>
			<type-mapping>PostgreSQL 7.2</type-mapping>
		</metadata>
	</local-tx-datasource>

</datasources>