I came across this same assert. Ran mysqlcheck and confirmed there is no data loss.
Can someone confirm if this assert implies a bug in source code or hardware ?

May  3 16:10:17 scdnwcb01 mysqld: 2016-05-03 16:10:17 7f91cd01a700  InnoDB: Assertion failure in thread 140264186423040 in file btr0pcur.cc line 447
May  3 16:10:17 scdnwcb01 mysqld: InnoDB: Failing assertion: btr_page_get_prev(next_page, mtr) == buf_block_get_page_no(btr_pcur_get_block(cursor))
May  3 16:10:17 scdnwcb01 mysqld: InnoDB: We intentionally generate a memory trap.
May  3 16:10:17 scdnwcb01 mysqld: InnoDB: Submit a detailed bug report to http://bugs.mysql.com.
May  3 16:10:17 scdnwcb01 mysqld: InnoDB: If you get repeated assertion failures or crashes, even
May  3 16:10:17 scdnwcb01 mysqld: InnoDB: immediately after the mysqld startup, there may be
May  3 16:10:17 scdnwcb01 mysqld: InnoDB: corruption in the InnoDB tablespace. Please refer to
May  3 16:10:17 scdnwcb01 mysqld: InnoDB: http://dev.mysql.com/doc/refman/5.6/en/forcing-innodb-recovery.html
May  3 16:10:17 scdnwcb01 mysqld: InnoDB: about forcing recovery.
May  3 16:10:17 scdnwcb01 mysqld: 16:10:17 UTC - mysqld got signal 6 ;
May  3 16:10:17 scdnwcb01 mysqld: This could be because you hit a bug. It is also possible that this binary
May  3 16:10:17 scdnwcb01 mysqld: or one of the libraries it was linked against is corrupt, improperly built,
May  3 16:10:17 scdnwcb01 mysqld: or misconfigured. This error can also be caused by malfunctioning hardware.
May  3 16:10:17 scdnwcb01 mysqld: We will try our best to scrape up some info that will hopefully help
May  3 16:10:17 scdnwcb01 mysqld: diagnose the problem, but since we have already crashed,
May  3 16:10:17 scdnwcb01 mysqld: something is definitely wrong and this may fail.
May  3 16:10:17 scdnwcb01 mysqld: Please help us make Percona XtraDB Cluster better by reporting any
May  3 16:10:17 scdnwcb01 mysqld: bugs at https://bugs.launchpad.net/percona-xtradb-cluster
May  3 16:10:17 scdnwcb01 mysqld:
May  3 16:10:17 scdnwcb01 mysqld: key_buffer_size=16777216
May  3 16:10:17 scdnwcb01 mysqld: read_buffer_size=131072
May  3 16:10:17 scdnwcb01 mysqld: max_used_connections=57
May  3 16:10:17 scdnwcb01 mysqld: max_threads=352
May  3 16:10:17 scdnwcb01 mysqld: thread_count=47
May  3 16:10:17 scdnwcb01 mysqld: connection_count=47
May  3 16:10:17 scdnwcb01 mysqld: It is possible that mysqld could use up to
May  3 16:10:17 scdnwcb01 mysqld: key_buffer_size + (read_buffer_size + sort_buffer_size)*max_threads = 156880 K  bytes of memory
May  3 16:10:17 scdnwcb01 mysqld: Hope that's ok; if not, decrease some variables in the equation.
May  3 16:10:17 scdnwcb01 mysqld:
May  3 16:10:17 scdnwcb01 mysqld: Thread pointer: 0x86b8f10
May  3 16:10:17 scdnwcb01 mysqld: Attempting backtrace. You can use the following information to find out
May  3 16:10:17 scdnwcb01 mysqld: where mysqld died. If you see no messages after this, something went
May  3 16:10:17 scdnwcb01 mysqld: terribly wrong...
May  3 16:10:17 scdnwcb01 mysqld: stack_bottom = 7f91cd019e50 thread_stack 0x30000
May  3 16:10:17 scdnwcb01 mysqld: /usr/sbin/mysqld(my_print_stacktrace+0x2e)[0x8e397e]
May  3 16:10:17 scdnwcb01 mysqld: /usr/sbin/mysqld(handle_fatal_signal+0x392)[0x65ea02]
May  3 16:10:17 scdnwcb01 mysqld: /lib/x86_64-linux-gnu/libpthread.so.0(+0x10340)[0x7f9301f88340]
May  3 16:10:17 scdnwcb01 mysqld: /lib/x86_64-linux-gnu/libc.so.6(gsignal+0x39)[0x7f93013c9cc9]
May  3 16:10:17 scdnwcb01 mysqld: /lib/x86_64-linux-gnu/libc.so.6(abort+0x148)[0x7f93013cd0d8]
May  3 16:10:17 scdnwcb01 mysqld: /usr/sbin/mysqld[0xaa8a0b]
May  3 16:10:17 scdnwcb01 mysqld: /usr/sbin/mysqld[0xa4515d]
May  3 16:10:17 scdnwcb01 mysqld: /usr/sbin/mysqld[0xa48b6e]
May  3 16:10:17 scdnwcb01 mysqld: /usr/sbin/mysqld[0x9a5c10]
May  3 16:10:17 scdnwcb01 mysqld: /usr/sbin/mysqld(_ZN7handler17ha_index_read_mapEPhPKhm16ha_rkey_function+0x7f)[0x5ac1df]
May  3 16:10:17 scdnwcb01 mysqld: /usr/sbin/mysqld[0x6c0e42]
May  3 16:10:17 scdnwcb01 mysqld: /usr/sbin/mysqld[0x6c034d]
May  3 16:10:17 scdnwcb01 mysqld: /usr/sbin/mysqld[0x6c009d]
May  3 16:10:17 scdnwcb01 mysqld: /usr/sbin/mysqld[0x6c03b8]
May  3 16:10:17 scdnwcb01 mysqld: /usr/sbin/mysqld(_ZN4JOIN4execEv+0x305)[0x6bf195]
May  3 16:10:17 scdnwcb01 mysqld: /usr/sbin/mysqld(_Z12mysql_selectP3THDP10TABLE_LISTjR4ListI4ItemEPS4_P10SQL_I_ListI8st_orderESB_S7_yP13select_resultP18st_select_lex_unitP13st_select_lex+0x255)[0x7085c5]
May  3 16:10:17 scdnwcb01 mysqld: /usr/sbin/mysqld(_Z13handle_selectP3THDP13select_resultm+0x18f)[0x708e6f]
May  3 16:10:17 scdnwcb01 mysqld: /usr/sbin/mysqld[0x562a9d]
May  3 16:10:17 scdnwcb01 mysqld: /usr/sbin/mysqld(_Z21mysql_execute_commandP3THD+0xd8c)[0x6e1a5c]
May  3 16:10:17 scdnwcb01 mysqld: /usr/sbin/mysqld(_ZN18Prepared_statement7executeEP6Stringb+0x390)[0x6fba20]
May  3 16:10:17 scdnwcb01 mysqld: /usr/sbin/mysqld[0x6fc653]
May  3 16:10:17 scdnwcb01 mysqld: /usr/sbin/mysqld(_Z19mysqld_stmt_executeP3THDPcj+0x475)[0x6fd5a5]
May  3 16:10:17 scdnwcb01 mysqld: /usr/sbin/mysqld(_Z16dispatch_command19enum_server_commandP3THDPcj+0xece)[0x6ea95e]
May  3 16:10:17 scdnwcb01 mysqld: /usr/sbin/mysqld(_Z10do_commandP3THD+0x1e3)[0x6eccb3]
May  3 16:10:17 scdnwcb01 mysqld: /usr/sbin/mysqld(_Z24do_handle_one_connectionP3THD+0x27d)[0x6b5a9d]
May  3 16:10:17 scdnwcb01 mysqld: /usr/sbin/mysqld(handle_one_connection+0x42)[0x6b5b82]
May  3 16:10:17 scdnwcb01 mysqld: /usr/sbin/mysqld(pfs_spawn_thread+0x140)[0x983bf0]
May  3 16:10:17 scdnwcb01 mysqld: /lib/x86_64-linux-gnu/libpthread.so.0(+0x8182)[0x7f9301f80182]
May  3 16:10:17 scdnwcb01 mysqld: /lib/x86_64-linux-gnu/libc.so.6(clone+0x6d)[0x7f930148d47d]
May  3 16:10:17 scdnwcb01 mysqld:
May  3 16:10:17 scdnwcb01 mysqld: Trying to get some variables.
May  3 16:10:17 scdnwcb01 mysqld: Some pointers may be invalid and cause the dump to abort.
May  3 16:10:17 scdnwcb01 mysqld: Query (7f915441cb68): is an invalid pointer
May  3 16:10:17 scdnwcb01 mysqld: Connection ID (thread ID): 232476
May  3 16:10:17 scdnwcb01 mysqld: Status: NOT_KILLED
May  3 16:10:17 scdnwcb01 mysqld:
May  3 16:10:17 scdnwcb01 mysqld: You may download the Percona XtraDB Cluster operations manual by visiting
May  3 16:10:17 scdnwcb01 mysqld: http://www.percona.com/software/percona-xtradb-cluster/. You may find information
May  3 16:10:17 scdnwcb01 mysqld: in the manual which will help you identify the cause of the crash.
May  3 16:10:18 scdnwcb01 mysqld_safe: Number of processes running now: 0
May  3 16:10:18 scdnwcb01 mysqld_safe: mysqld restarted